









j * -V 1 /y> - " 0 

i * o / t 


AV < 0 ® * <?-, 



.... * 


>*• 




o >> 


A. 0 * v ’\'"TTrs-\\ , 



•y v- 
O > 



vv ;,5 



J x u ^ - _„... 

* o *-.• 

* 8 I £°‘ s » * ,. *>. * 0 f 

"• \* <A * ^W% * •- 

^7> <X S 


„A ,fl ~ 

. A 5 <p. J. 

* »3 C” •* c£* ' % 

< y 0 * V * ^0 ’-?^ ' » 6 S S \ 

- <* .0^ < 0 K c * *0- 

*"? i J 1}. r^rv_ ^ < t) 4 . 

^ *? 


■# V % ° 



^ ^ ^ oV 

' \ A C 0 * * ^ 

, -O ,/.v*_^, % ,/ . 

*b>* 

'&MS& * \° -r. 


v 


- +* * 

2 ^ $* ° 
o . \> 

* Av ^ ° 

J- V ^ \ ■ J ’ a. >3 c^ -4 o’ 

t0 ^'^^ / ‘* S </ 

,\ * ^ ? ^ 


% v\V 


S - - 'X - £>AS 

r - V 5 ^ : 11 
-* oV •%. *M 




■i>, * i 

r < 5 V^s' A 

rP v ' c»: c .\: ** W" 



aV /'■* ^ 

' •*> v^ N -Mk : ^,, * ~ 

f ° ■ * JAf : ;■ ' 

* \0 ^ * 

Y-‘ Cj_ s (AJ ck r N1 A-s J ~ « y, _ 

, \* Y * 0 ^ »>n* / _ ^ * .0 N O *> o » 9 , 

•A -jBr, ^ » £mk'- a A ;4&%° A 


O 




< ' A \ . I I fi 

, ^ vA N - r $m^> * Kf> t <. 

* O v * A 0 V 

; x° ^ * 

.0 “‘ ' 




» 

*»■ 

^/// ■ ^ ^ o. 

c o. ,o° ^ % . 

. 81 ' o> 3N 

r , ^V. <* •*■ 


o 

A 


A* 

4 ♦* ^ ’-^^ 4 - ^ 

/v" - y °-‘* - 1 '' 





*H rv N 

,-0 v I . 





























^ .4 

» * s S . \ 


4 oV* *• ^ <\v c V/IW, v>. 

\0 O 'tj*^*<^* \ J ^ ;- ,_•• " ^ o_V ^ 

a? . 0 N r ; , '/-• y * * s A ' . o <b •' o n i * <0 O -V , 

0° *\^ % °0 ,1? V* 1 ' % ^ 0^ c oK& « *‘ S ’a\\ *' 1 

4 A A * /K/rTfo? + ** c v * ^>Cv . <* -J> .!* V 

* ° ^ '■ ^ o N c 

. OA „ •> 

£>o o5 - ^, //JIW 

> V s <* < r^//iw ? 

* A.' r* /- ^Lt*f ^ c 


- t< A-f 


« 


^ O 1 1 8 4 ^ ' 0 * x * 



c* ^ 

■s 

* 9 

1 A S 

c> 


<= 

y<- 


1 o -<S’ 

7 , ^ 



aO O 7 . s X A 

0^ c« N «, '**' a\ X 

Vj + r^N\ Z f *6 ' 


.^'G »* v> 

■ *■ - v%^.* „v 



7 & a ^nr^\© A <b, 

. .,«.>*/ °<*^V s,'* 



° A^ ^ ° 

^ >?• ^ 




% ^ 
'O (\v 


^ z *^» 4 

* / ^ "* 

y o * * ^ ,\ 

ft? 0 N c a\ , v IB 

" *„ CP °C ,# Ow 


\V < 


* o' ; % 

° o5 ^ 

^ c* % ~ C W* V ^ 0 

°* ■Vo.,* a0 

V * ,. 

a js, .Wr ^ ,**V 

'V V- - V * 

* O^V y ■^W^fax N 


« aV 
♦ # ^ 




C.S - 

y 

,0^ c 0 N 

^ o' :'C?f^: 'bv*' o' ' »* 

vm/V \W$- *1 ■ 
y.„ %‘/;:, y s ..,v-"r:>*,/ - 0 \ 

V ^ r c* xO <. s ^ r *f > . \ v „ x * 0 „ ’n 

^ n\- * A'A. p . <v> ^ rarai o ^ ^ 






l >* 5 

^ «D s s % A 

<- 0 S f ‘ 4 * G. <« ' 1 k -. - 

’a/, ° % 




,y> •>■ /, s 


\ x f\0 & y 

" 91 ' oV s v ’ s 5 N ° 

v ^ 



f 




a .>> a 

^ A\V ^ 
V^V - rS 




^ : a ^ , 

' 0 > S*'* ,0^’ ^ y * 



^ r 0 X 



\° -r 

A V> 

'i* C\ ^ ^ • 

o- "* ' <0- ^ y > ^ . 

A- » I ' N. <,-»«* V, O N c 

^ <A ^ * *^ 

o V V u 

; ^ v % ,/^ 

^'"’V".V # *‘V%- 

- y -k« ° * 

; -"o v ‘ * - • ^ 




V- ^ 





























MODERN AMERICAN MACHINE TOOLS 







ODERM AMERICAN 


MACHINE TOOLS 


BY 


C. H. BENJAMIN 

IJ 

PROFESSOR OF MECHANICAL ENGINEERING, CASE SCHOOL OF 
APPLIED SCIENCE, CLEVELAND, OHIO, U.S.A. 

MEMBER OF AMERICAN SOCIETY OF MECHANICAL ENGINEERS 


WITH 134 ILLUSTRATIONS 


NEW YORK 

E. P. DUTTON AND COMPANY 






Edinburgh : T. and A. Constable, Printers to His Majesty 



THIS BOOK 
IS DEDICATED TO 

ALBION P. BENJAMIN 

WHO FIRST SHOWED ME 
THE RIGHT AND WRONG OF 


MACHINE CONSTRUCTION 









































PREFACE 


Such books on machine tools as have been published hitherto 
have treated the subject mainly from the standpoint of the 
apprentice or the journeyman, and have described the details 
of adjustment and operation rather than the design and 
construction of the machines themselves. It is the object 
of this treatise to show to the buyer and user the pro¬ 
minent characteristics of modern machine tools as now 
manufactured in the United States, the various points in 
which they differ, and some recent data as to their capacity 
and performance. It is hoped that this book may also be 
of interest and profit to the manufacturer of metal-working 
machinery as showing the general trend of machine design 
and the more recent developments. 

To the buyer in Great Britain or on the Continent this 
work should be a help, as it brings together in one volume 
facts from a variety of sources, and furnishes information 
which might otherwise need to be sought at much expendi¬ 
ture of time and trouble. 

In deciding upon the types of machines to be considered, 
it has been thought best to exclude special machinery which 
is used for a limited line of manufacture, and to include 
only those machines which would find use in a general 
machine shop. 

The list then includes planing, turning, boring, and drill¬ 
ing machinery, milling and grinding machines, and finally 





viii MODERN AMERICAN MACHINE TOOLS 

machinery for shearing and punching metal and for cutting 
screw threads. 

Chapter XII. aims to give a review of the subject of 
machine-tool design, to show recent improvements, and the 
direction in which to look for further progress. 

While the present work is in no sense an advertising 
medium, an endeavour has been made to illustrate as large 
a variety of machines and of makes as the limits of space 
would allow. 

The writer wishes to acknowledge his indebtedness to 
the manufacturers whose kindness in the matter of furnish¬ 
ing photographs has made possible the illustration of the 
book, and to express his regret that the natural limita¬ 
tions of space have made it impossible to illustrate all the 
machines mentioned. 










TABLE OF CONTENTS 



CHAPTER 

I 



PLANING MACHINES 


ARTICLE 


PAGE 

1. 

Classification, 


1 

2. 

Planing Machines, 

# 

2 

3. 

Planer Beds, 


2 

4. 

The Table, 


5 

5. 

The Housings, 

o • . 

6 

6. 

The Cross-Rail, 

. 

10 

7. 

The Tool Head, 


13 

8. 

The Gearing for Table, 

• • • 

14 

9. 

The Reversing Gear, 

• 

. 17 

10. 

The Feed Mechanism, 

• • • 

18 

11. 

Widened Planers, 

. 

19 

13. 

Open-Side Planers, 

• • • 

. 20 

13. 

Combination Planers, 

• • 

22 

14. 

Cutting Speeds, . 

• 

24 

15. 

Horse-Power, 

. • • 

25 

16. 

Electric Drives, 

. 

. 27 


CHAPTER 

II 



CRANK PLANERS, SHAPERS, AND 

SLOTTING MACHINES 


17. 

Crank Planers, 


. 32 

18. 

Shaping Machines, 

. 

33 

19. 

The Column, 

. 

34 

20. 

The Ram, 

• 

35 

21. 

The Tool Head, . 

. 

36 

22. 

The Cross-Rail, 

• 

. 38 

23. 

The Table, 

• • 

. 38 


IX 













X 


MODERN AMERICAN MACHINE TOOLS 


ARTICLE 

24. The Driving Gear, 

25. The Feed Mechanism, 

26. The Countershaft, 

27. Electric Driving, . 

28. Traverse Machine, 

29. Open-Side Shaper, 

30. Draw-Cut Shaper, 

31. Slotting Machines, 

32. Key-Seating Machines, 

33. Rotary Planing Machines, 

34. Heavy Milling Machines, 

35. Miscellaneous Machines, . 


CHAPTER III 

ENGINE LATHES 

36. Lathes in General, 

37. The Bed, .... 

38. The Headstock, 

39. The Spindle, 

40. Speed Gearing, 

41. Feed Control, 

42. The Carriage, 

43. The Apron, 

44. The Tail- or Foot-Stock, . 

45. General Considerations, . 

46. Cutting Speeds, . 

47. Horse-Power of Lathes, . 

48. Electric Drives, . 



83 

87 


92 


CHAPTER IY 

SPECIAL LATHES, INCLUDING TURRET LATHES 


49. Gap and Extension Lathes, . . . . .97 

50. Two-Spindle Lathes, . . . . .99 

51. Reduction or Roughing Lathes, . . . . .99 

52. Stud and Bolt Lathes, . . . , 102 


















CONTENTS 


XI 


ARTICLE PAGE 

53. Tool-Maker’s Lathe, . . . . . .102 

54. Facing Lathes, . . . . . . .102 

55. Railroad Machinery, . . . . . .103 

56. Miscellaneous, . . . . . . .104 

57. Turret Machinery, . . . . . .106 

58. The Turret Lathe, . . . . . .107 

59. Hollow Hexagon Turret, . . . . .110 

60. Flat Turret Machine, . . . . . .112 

61. Automatic Lathe or Chucking Machine, . . . .114 

62. Turret Tool-Post Lathe, . . . . . .115 

63. Forming Machines, . . . . . .118 

64. Automatic Screw Machine, . . . . .120 

65. Automatic Chucking Machine, . . . . .121 

66. Vertical Turret Machine, . . . . .123 

67. Power and Capacity, . . . . . .124 

CHAPTER V 

BORING MILLS, VERTICAL AND HORIZONTAL 

68. Vertical Boring and Turning Machinery, . . .126 

69. Single-Post Machines, . . . . . .127 

70. Machines with Two Housings, . 128 

71. The Table, . . . . . . .129 

72. The Housings, . . . . . • .133 

73. The Cross-Rail, . . . . . . -133 

74. The Tool Heads, . . . . • .135 

75. The Feed Mechanism, . . . . • .137 

76. The Driving Mechanism, . . . .139 

77. Electric Transmission, . . . . • .139 

78. Power and Capacity, . . . . • .141 

79. Mills with Movable Housings, . . . • .144 

80. Horizontal Boring Machines, . . . • .144 

81. Machines with Stationary Heads, . . • .146 

82. The Frame, . . . • • • .146 

83. The Boring Head,.148 

84. The Table, . . . . • • -l 49 

85. Speed and Feed Mechanism, . . • • .149 












xii MODERN AMERICAN MACHINE TOOLS 

article 

86. Capacity and Weight, 

87. Machines with Sliding Head, 

88. Large Machines, . 

89. Tilting Table, .•••*’ 

90. Cylinder Boring Machines, • 

91. Miscellaneous Machines, . 


CHAPTER VI 

DRILLING MACHINERY 

92. The Upright Drill, 

93. The Column, . 

94. The Head and Spindle, 

95. The Table, .... 

96. The Gearing and Feed Mechanism, 

97. Radial Drills, .... 

98. The Column and Base, 

99. The Radial Arm, 

100. The Tool Head, .... 

101. The Driving Mechanism, 

102. The Feed Mechanism, 

103. Speeds and Feeds, 

104. Tables, ..... 

105. Power and Capacity, 

106. Miscellaneous Machines, 

107. Multiple Drills, .... 

108. Power required for Drilling, 

109. High-Speed Drilling, 


CHAPTER VII 

MILLING MACHINES 


PAGE ,c 

150 ,5 
150 1( 
153 ; 
155 L 
155 |c 



160 I 

160 p 
164 p 
166 
168 

171 

172 
175 1 
178 1 
178 | 
182 | 
183 | 

185 ; 

186 
188 ' 
188* 
194 
196 j 


110. Advantages, . . . . . . .198 

111. Classification, . . . . . . 198^ 

112. Column Machines, ...... 199 

113. The Column, ....... 199 

114. The Table, . . . . . . .201 











CONTENTS 


Xlll 


article 

115. The Spindle and Head, . 

116. The Driving Mechanism, 

117. Feed Mechanism, 

118. Attachments, 

119. The Universal Head, 

120. Chucks and Vices, 

121. Spindle Attachments, 

122. High-Speed Milling, 

123. Lincoln Milling Machines, 

124. The Manufacturing Machine, 

125. Profiling Machines, 

126. Vertical Milling Machines, 

127. Power and Capacity, 


PAGE 

203 

206 

207 

211 

212 

213 

215 

216 

217 

218 
221 
223 
226 


CHAPTER VIII 

GEAR CUTTING 

128. Gear Cutting in General, 

129. Automatic Machines, 

130. Gear-Shaping Machines, 

131. Gear-Planing Machines, . 

132. Thread-Milling Machines, 

CHAPTER IX 

GRINDING MACHINERY 

133. Grinding in General, 

134. Classification, .... 

135. Surface Grinding, 

136. Disc Machines, . 

137. Ring Wheels, .... 

138. Machines with Cylindrical Wheels, 

139. Cylindrical Grinding Machines, 

140. Universal Grinding Machines, . 

141. Tool Grinders, .... 

142. Twist-Drill Grinders, 


229 

230 
237 
242 
245 


249 

249 


250 

252 

253 
255 
257 
262 
265 


269 


















XIV 


MODERN AMERICAN MACHINE TOOLS 


ARTICLE 

143. Cutter and Reamer Grinders, 

144. Emery Wheels, . 


CHAPTER X 

PUNCHING AND SHEARING MACHINERY 

145. Pressure Machines .... 

146. The Frame, ..... 

147. Pressure Mechanism, .... 

148. The Disengaging Clutches, 

149. The Driving Mechanism, 

150. The Tools, . . . . . 

151. The Lever Shear, ....*' 

CHAPTER XI 

SCREW-CUTTING MACHINERY 

152. In General, ..... 

153. The Die Head, ..... 

154. The Driving Mechanism, 

155. Carriage and Feed Mechanism, . 

156. General Design, ..... 

157. Feeds and Speeds, .... 

158. Nut-Tapping Machinery, 

159. Thread-Rolling Machines, 

CHAFTER XII 

TENDENCIES IN MODERN MACHINE DESIGN 

160. General Remarks, .... 

161. Electric Driving, ..... 


Index, . 














LIST OF ILLUSTRATIONS 


FIGURE 

1. Whitcomb Planing Machine, . 

2. Betts Planing Machine, 

3. Oiling Planer Ways, 

4. Y for Heavy Planer, 

5. Gray Frog and Switch Planer, . 

6. Gray Widened Planer, . 

7. Woodward and Powell Planer, . 

8. Spiral Gear Drive, 

9. Second Belt Drive, . “ . 

10. Open-Side Planer, 

11. Flather Combination Planer, 

12. Electrically-Driven Planer, 

13. Do. do. do., 

14. Whitcomb Crank Planer, 

•15. Steptoe Geared Shaper, 

16. Flather 24-inch Shaper, 

17. Crank Shaper, Electric Drive, . 

18. Cincinnati Traverse Shaper, 

19. Morton Draw-Cut Shaper, 

20. New Haven Slotting Machine, . 

21. Baker Draw-Stroke Slotter, 

22. Sellers Rotary Planer, . 

23. Hess Heavy Milling Machine, . 

24. Ingersoll Heavy Milling Machine, 

25. American Engine Lathe, 


PAGE 

3 

4 

5 

6 
8 
9 

11 

15 

16 
21 
23 
28 
30 
33 
35 
37 
39 
41 

46 

47 

50 

51 
53 

. 55 
59 


XV 









XVI 


MODERN AMERICAN MACHINE TOOLS 


FIGURE 

26. Lodge and Shipley Engine Lathe, 

27. Le Blond Engine Lathe, 

28. Schumacher and Boye Lathe, . 

29. Pond 54-Inch Lathe, 

30. Headstock of Lathe, 

31. Bo. do., 

32. Bradford Engine Lathe, 

33. Triple-G-eared Head, 

34. Standard Lathe Apron, 

35. Carriage of Bradford Lathe, 

36. Inside of Lathe Apron, 

37. American High-Speed Lathe, . 

38. Electrically-Driven Lathe, 

39. Do. do. do., 

40. Harrington Extension Lathe, . 

41. iVPCabe Double Spindle Lathe, 

42. Le Blond Roughing Lathe, 

43. Tool-Maker’s Lathe, 

44. Bement Driving-Wheel Lathe, . 

45. Turret Engine Lathe, . 

46. Pratt and Whitney Turret Lathe, 

47. Section of Turret, 

48. Hexagon Turret Lathe, 

49. Jones and Lamson Flat Turret, 

50. Gisholt Turret Lathe, . 

51. Bardons and Oliver Forming Machine, 

52. Automatic Chucking Machine, . 

53. Niles Turret Boring Mill, 

54. Table and Spindle, 

55. American Boring Mill, . 

56. Baush 51-inch Boring Mill, 

57. Bickford 72-inch Boring Mill, . 

58. Pond 10-foot Boring Mill, 

59. Betts 12-foot Boring Mill, 












LIST OF ILLUSTRATIONS 

xvii 

FIGURE 



PAGE 

60. 

Electrically-Driven Boring Mill, 


142 

61. 

Horizontal Boring Machine, . 


147 

62. 

Do. do. do., 


151 

63. 

Large Horizontal Boring Machine, 


154 

64. 

40- Inch Horizontal Boring Machine, . 


156 

65. 

Two-Spindle Boring Machine, 


158 

66. 

Slate Sensitive Drill, . 


161 

67. 

American Upright Drill, 


163 

68. 

Snyder Upright Drill,. 


165 

69. 

Niles 60-Inch Upright Drill, . 


167 

70. 

Baker Heavy Upright Drill, . 


170 

71. 

American Plain Radial Drill, . 


171 

72. 

Bickford Half-Universal Drill, 


173 

73. 

Column of Radial Drill, 


174 

74. 

Fosdick Radial Drill, . 


176 

75. 

Dreses Radial Drill, . 


179 

76. 

Niles Universal Radial Drill, . 


181 

77. 

Electrically-Driven Radial, 


187 

78. 

Pratt and Whitney Multiple Drill, 


190 

79. 

Niles Multiple Drill, . 


191 

80. 

Baush Horizontal Multiple Drill, 


193 

81. 

Kempsmith Milling Machine,. 


200 

GO 

JO 

Le Blond Milling Machine, 


202 

83. 

Cincinnati Milling Machine, . 


204 

84. 

Brown and Sharpe Milling Machine, . 


209 

85. 

Spindle of Milling Machine, . 


211 

86a, 

Universal Dividing Head, 


214 

m. 

Do. do. do., 


215 

86c. 

Do. do. do., 


216 

87. 

Kempsmith Lincoln Miller, 


219 

88. 

Newton Duplex Milling Machine, 

• 

220 

89. 

Two-Spindle Profiling Machine, 

• 

222 

90. 

Spindle of Profiling Machine, . 

• 

224 

91. 

Vertical Milling Machine, 

• 

225 


b 







XV111 


MODERN AMERICAN MACHINE TOOLS 


PAGE 


FIGURE 

92. Heavy Vertical Milling Machine, 

93. Brainard Gear Cutter, . 

94. Brown and Sharpe Gear Cutter, 

95. Gould and Eberhardt Gear Cutter, 

96. Fellows Gear Shaper, . 

97. Action of Gear Shaper, 

98. Gleason Gear Planer, 

99. Cutter Arm of Gleason Planer, 

100. Thread Milling Machine, 

101. Universal Disc Grinder, 

102. Ring Wheel Grinder, 

103. Open-Side Surface Grinder, 

104. Method of Turning Blanks, 

105. Norton Grinding Machine, 

106. Landis Universal Grinding Machine, 

107. Do. do. do., 

108. Brown and Sharpe Grinding Machine, 

109. Sellers Tool Grinder, 

110. Gisholt Tool Holder, 

111. Grinding Twist Drills, . 

112. Worcester Drill Grinder, 

113. Cincinnati Tool Grinder, 

114. Norton Tool Grinder, . 

115. Brainard Cutter Grinder, 

116. Frames of Shear Presses, 

117. Large Punching Press, . 

118. Cleveland Horizontal Punch, . 

119. Lever Shear, Motor Driven, 

120. Adjustable Plunger, 

121. Do. do., 

122. Punch with Stayed Gap, 

123. Vertical Shear Press, . 

124. Perkins Automatic Clutch, 

125. Motor-Driven Lever Punch, 


227 
231 
233 ; 
236 j 
238 ! 
240 t 
242 | 
244 { 
246 | 
251 | 
254 
256 
258 

< 

260 

261 

263 

264 

267 

268 ] 
270 
272 
274 

276 

277 
281 
282 

283 

284 | 

285 

285 

286 

287 

288 
290 


j 















LIST OF ILLUSTRATIONS xix 

FIGURE PAGE 

126ft. Acme Die Head, ...... 294 

1266. Do. do., ...... 295 

127. Morgan Die Head, . . . . . .296 

128. Landis Die Head, ...... 297 

129. Acme Bolt Cutter, ...... 298 

130. Pipe Threading Machine, ..... 299 

131. Pond New Model Lathe, . . . . .310 

132 Bardons and Oliver Forming Lathe, .... 312 

133. New Flat Turret Lathe, . . . . .314 

134. 30-Inch Patent Head Lathe, . . . . .316 














' 


CH A PTE ll I 

t 

PLANING MACHINES 

» 

i. Classification. 

i 

i 

Machines for producing plane or flat surfaces may be 
1 classified under the head of planing machines proper, or, as 
they are usually called, ‘ planers,’ shaping machines or 
shapers, slotting machines or vertical shapers, milling or 
slabbing machines, and the so-called rotary planers. 

Briefly described, the planer has a platen or table which 
■carries the work against the cutting 1 tool and back, the 
tool having only the transverse motion necessary for the 
feed. 

The shaper, on the other hand, has a cutting tool which 
'moves back and forth over the work, the latter in turn 
having the transverse motion of feeding. 

o o 

The slotting machine is in the same general class as the 
shaper, but the tool slide has a vertical instead of a horizontal 
motion. 

The milling machine with its rotary cutters belongs in 
a class by itself and is almost universal in its application, 
but in the form known as a slabbing machine develops flat 
tsurfaces only and is a formidable rival of the planer. 

The so-called rotary planer, while closely allied to the mill¬ 
ing machine, is usually distinguished by the use of a revolving 
head of large diameter carrying on its flat face removable 
cutters or tools. Its peculiar held is the facing of ends on 
, columns or frames. 


A 


9 


MODERN AMERICAN MACHINE TOOLS 


2. Planing Machines. 

The principal elements of a planing machine are : (a) the 
bed or frame; (b) the table carrying the work; (c) the 
vertical housings connected by the top brace ; ( d) the cioss- 
rail, carrying one or more heads and adjustable vertically on 
the housings ; (e) the tool heads, similar to the compound 
rest of a lathe, attached either to the cross-rail or to the faces 
of the housings, and capable of motion vertically or hori¬ 
zontally ; (/) the gearing for reciprocating the table ; (g) the 
shipping or reversing gear ; (li) the feed mechanism lor operat¬ 
ing the tool heads. 

3. Planer Beds. 


The bed of a planing machine varies with the type and . 
size of machine. In general it consists of a hollow, rect¬ 
angular casting with or without legs, having ways at the top 
for the guidance of the table and provided with bosses and ( 
projections for the attachment of the shafts and gearing. In 
small planers, ranging from 17 inches to 30 inches capacity, 
it is necessary to support the bed on legs in order to secure 
the necessary height of table for the convenience of the work¬ 
man. Fig. 1 shows a good example of modern design for a 
17 x 17' x 4' machine. There is an entire absence of orna- i 
ment and filigree work, only plane surfaces being used ; the' 
bed overhangs the legs so as to divide up the bending 
moment, and to make it easier for the workman in getting 
around the end of the machine. The outer ends of the bed 
are cut away so as to give a shape of approximately uniform 
strength. The length of the bed should be such as to* 
support the table throughout the full stroke, and such that, 
when the table is run entirely out of gear, it cannot tip up. 

Some American makers quote 20 inches length of bed for 
every foot of table length. Cabinets may be substituted for 
legs in machines of larger capacity and give greater stability 






PLANING MACHINES 3 

without being in til© way of tlio operator. In general tins 
is a neat design, but it is not considered good practice to have 
the ways overhang the bed at the ends. 

Some makers use a third leg or support under the middle of 


the length of bed, but this arrangement must be condemned. 
In planing machines so small as to require the use of legs the 
bed itself should be strong and stiff enough to carry all the 
load. A middle leg rarely takes its fair share of the weight, 
and, as one designer puts it, ‘ Its only use seems to be to 
hold the floor down.’ 


The Whitcomb Manufacturing Co., Worcester, Mass. 


Fig. 1. 

17"x 17"x4' PLANING MACHINE. 














MODERN AMERICAN MACHINE TOOLS 


As the size of the machine increases, the bed becomes 
deeper and the legs shorter, but the same general outline is 
preserved. 

In the larger sizes of planers, from 48 inches upward, the 
legs disappear altogether and the bed becomes a plain box of 
cast iron resting on a stone or concrete foundation. Not alone 


Fig. 2. 

48-INCH PLANING MACHINE. 

The Betts Machine Co., Wilmington, Del. 

strength and rigidity are needed in this size of machine, but 
the bed must possess inertia and be anchored like an engine 
frame to withstand the shock of reversal. Fig. 2 illus¬ 
trates this form of bed as used with a 48-inch pfaner. All 

of the beds illustrated are stiffened laterally by a system of 
interior cross-girts. 

The ways for guiding the table are usually of the V form in 

















PLANING MACHINES 


5 


lo 


American practice, as this shape is readily lubricated and is 
self-adjusting lor wear. Planers for heavy service, however, 
are sometimes equipped with flat 
ways, and in this case the table 
x has gibbed slides to hold it in 
place. 

The lubrication of the V’s of 
planing machines, especially in the 
larger sizes, is effected by conical 
brass rolls (Fig. 3) dipping into oil- 
pockets and carrying the oil up to 
the ways as they revolve with the 
friction of the table. 

Similar rolls of a cylindrical form 
are used with the flat ways. For 
extremely heavy pressures the flat 
way is undoubtedly the best as it 

is free from wedge action, but for ordinary service the V 
is easier to fit and to keep in repair. 



Method of Oiling 
Planer Ways. 


4. The Table. 


The principal duties of a planer table are to move smoothly 
and accurately upon the bed, and to keep its top surface at all 
times true and straight. It should be made of a moderately 
hard, close-grained iron, be of sufficient depth, and be 
thoroughly braced by longitudinal and transverse ribs under¬ 
neath. There are two principal methods of driving, by spur 
gearing and by spiral gearing. These will be discussed in 
another place, and it is only necessary here to call attention 
to the necessity of smooth action and of sufficient strength in 
the gearing. The best American machines now have steel 
racks and pinions for driving the table, with teeth accurately 
cut by machinery. 


The width of rack for machines 


from 


24 


to 48 inches in 



















6 



MODERN AMERICAN MACHINE TOOLS 

capacity is from 4 to 6 indies. The angle of the \ s vanes 
somewhat in different sizes and types of planers, but is 
usually 90 degrees. In general this angle will be less for 
small machines, and greater for planers which are intended 
for heavy work. Instead of flat ways a very obtuse V with 
side edges is sometimes used as shown in I ig. 4. 1 he I slots 

in the top of the table should be 
planed so that bolts may be easily 
slid from one position to another. 1 
It is extremely convenient in clamp¬ 
ing long work to have one slot ex¬ 
tend completely through the table. 
The holes for pins should all be 
reamed to a standard size, as nothing 
is more annoying than to have pins 
too loose or too tight in fastening 
work. All tables should have a 
depression at each end to catch oil and chips. It is, 
however, convenient to have pin-holes at the extreme 
outer end. 


Broad V for Heavy 
Planer. 


5. The Housings. 


The upright standards to support the cross-rail, or the 
housings as they are usually called, are a very important part 
of the design. They take the whole thrust of the cutting 
tools and the shock of the beginning of the cut; they must be 
strong enough to withstand this thrust when the cross-rail 
is raised to its highest position, and must he stiff enough 
transversely to sustain the pressure of side cuts. It is hard 
to say just how strong and stiff they must be, but the 
stronger and the stiffer the better. The union of a deep bed 
with deep housings has been the principal cause of the 
increase in capacity of planing machines. 

Formerly a planer was limited by its own slenderness 









PLANING MACHINES ' 7 

and fragility ; now the limit is usually the endurance of the 
cutting tool. 

The housing of a planing machine when the cross-rail is at 
the top is in the condition of a bracket fixed at one end and 
loaded at the other. If of constant breadth from top to 
bottom, its profile should be a parabola with axis vertical and 
vertex at the load-point, to secure the maximum strength 
for a given weight. This form is approximated to in most 
American machines, as may be seen by reference to the 
illustrations. To secure lightness without much sacrifice 

O 

of strength two or more circular holes are cut along the 

O O 

line of the neutral axis. These holes must be kept well 
away from the front vertical face, as this side is exposed to 
tension. 

As the casting is usually of box form and cored, these aper¬ 
tures are available for core prints. Some makers prefer to 
cut apertures in such a way as to give the appearance of 
straight bracing as shown in Fig. 1. If properly calculated, 
this form may be made to give good results. Others prefer 
to use the straight line altogether as shown in Fig. 5. It 
should be said, however, that this latter machine is intended 
especially for heavy work near the table, and that with the 
cross-rail in its highest position there would be more deflec¬ 
tion than if the parabolic housing were used. 

The housings are usually secured to projecting cheeks on 
each side of the bed by bolts and by planed lugs and grooves. 
In large planers the housing should extend to the bottom ol 
the bed and have a wide bearing surface in order to give a 
good leverage against the thrust of the cutting tool. lig. 2 
shows this clearly. 

Those machines are to be preferred in which the housings 
are kept reasonably near together. The attempt to make a 
42-inch out of a 36-inch planer by simply setting the hous¬ 
ings wider apart should be discouraged. 

The so-called ‘ widened planer’ has a place of its own like 
the gap lathe, and does not come under the above criticism. 





36-INCH FROG AND SWITCH PLANER 











PLANING MACHINES 


9 


Fig. 6 shows a planer of this description, especially adapted 
to handling work which is unusually wide in proportion to its 



Fig. 0. 

SPIRAL GEAR WIDENED PLANER. 

The G. A. Gray Co., Cincinnati, Ohio. 

height. This may be regarded as a special machine, and will 

be discussed under that head. 

A criticism sometimes made in regard to modern planing 
machines is that too little attention has been paid to the 
transverse stiffness of the housings and the ability to lesist 




























10 


MODERN AMERICAN MACHINE TOOLS 

the pressure of the tool when taking a heavy side cut. I he 
small width as compared with the depth of most planei 
housings seems to afford ground for this criticism, and some 
designers have proposed to put on heavy side flanges to resist 
the transverse pressure. These would interfere seriously with 
the convenience of the operation and with the arrangement of I 
the feeding and adjusting mechanism. It must be remem¬ 
bered that in resisting side thrust the two housings and the 
top brace act as a unit, or rather as a braced structure. It 
the housings have proper depth of contact with the sides of 
the bed and are firmly connected at the top to a deep, well- 
designed top brace, the structure as a whole will have great 
lateral stiffness. This is well shown in Fig. 2. Especial 
attention should be given to securing the top brace firmly 
and rigidly to the housings. 

The vertical ways on the face of housings should be wide, 
both for the sake of ample bearing surface for cross-rail and 
to give lateral stiffness to the housings themselves. 

O v - 

On small planers without side heads the ways need only 
come down near the table as in Fig. 1, but where side 
heads are used the ways should extend well below the table 
as in Fig. 2. 

6 . The Cross-Rail. 

Thus far the discussion has been confined to the main 
framework of the machine, where the desired features are 
strength, rigidity, and large bearing surfaces. There still 
remains the mechanism for controlling the feed of the tool 
and the reversal of the machine. While strength and 
durability are of prime importance, adaptability and con¬ 
venience must still be considered. In examining a machine 
tool one should ask first : c Is it strong enough to do the 
work ? ’ and second : ‘ Will it be a convenient machine to 
use, and will it give an output corresponding to its size 
and cost ? ’ 





Ihe Woodward and Poxcell Planer Co,, Worcester, Mass. 















12 


MODERN AMERICAN MACHINE TOOLS 


The cross-rail, so-called, is designed to carry the tool 
head or heads, and to provide proper adjustments and feeds 
for the operation of the cutting tool. The cross-rail is raised 
or lowered on the housings by means of vertical screws, and 
is so gibbed that it may be firmly clamped at any height. 
In small planers, as in Fig. 1 , the rail is raised or lowered 
by means of a horizontal shaft on the top brace, which is 
geared to both screws. This should have cranks at both ends, 
so that the rail may be adjusted from either side. Rails were 
formerly clamped to the ways on the housings by bolts and 
nuts on either side, requiring a trip around the machine and 
back every time a change was made. 

Some of the modern planers have a clamping device for 
this purpose which may be operated by a convenient lever. 
Usually all planing machines with a capacity of 30 inches 
or over have means of raising or lowering the cross-rail by 
power. This consists of a separate shaft driven by the over¬ 
head countershaft and gearing with the horizontal shaft on 
the top brace, as may be seen by reference to Figs. 2 and 7. 
Fig. 7 a t so shows the means of counterbalancinof the rail to 
ensure easy adjustment. 

For strength and rigidity the rail should have consider¬ 
able vertical depth and be well braced in the rear between the 
housings so as to approximate to a beam of uniform strength. 
The vertical depth gives it a good bearing on the ways, and 
prevents that twisting action so fatal to accuracy of cut. 
Some cross-rails have a parabolic brace at the rear ; this is 
naturally located near the bottom rather than at the top of 
the rail, as it is there that the thrust of the tool is most felt. 

The rail should extend horizontally on either side so that 
the tool head may be moved out and permit cutting the full 
width between the housings, even when swivelled at 45 
degrees for an under cub. Fig. 2 illustrates this very clearly. 
When two heads are used it is good practice to allow an 
extra length on the back side of the machine, so that the 
further head may be set over out of the way and the nearer 


PLANING MACHINES 


13 


head have the full range of width between housings. Fig. 6 
shows this feature. 

7. The Tool Head. 

In discussing this important feature of the modern plan¬ 
ing machine a distinction will be made between heads for 
small and large planers. Both types possess the same 
general adjustments, vertical, horizontal, and angular. Both 
are clamped to saddles which slide on the cross-rail. 

The saddle in all American planers has a rectangular slide 
at the top and an angular slide at the bottom, as may be seen 
by reference to Fig. 5 and in many of the other illustrations 
as well. The square guide and gib at the top prevent the 
saddle from tipping forward under the leverage of the cutting 
tool. The angular slide at the bottom permits of easy 
adjustment for wear. The saddle is moved horizontally by 
the cross-feed screw, and should have a clamp to hold it 
rigidly in one position when taking a heavy side cut. Such 
a clamp may be seen in Fig. 1, which illustrates the usual 
type of head for small planers. 

The tool post consists of a clamp with two bolts and 
hardened corrugated cheeks to support the tool. The 
arrangement is pivoted for lifting on the return stroke and is 
also swivelled to the vertical slide, that the tool may be so 
set as to lift away from the work 011 a side cut. The vertical 
slide is of the dove-tail type with an adjustable gib at one 
side, and is actuated by a left-hand screw. All modern 
planers are equipped with a power feed for this slide, driven 
by a splined rod and gears similar to those on a lathe. 

A turn-table behind the slide makes it possible to take 
side cuts at any angle. 

On larger machines such as that shown in Fig. 7 two heads 
are usually employed, and these are of a much more massive 
construction. Four clamping bolts are used instead of two, 
and more bearing is given behind the tool. The heads are 











14 


MODERN AMERICAN MACHINE TOOLS 


sometimes offset right and left to make it possible for tools' 
to work close together. 

A counter-balance is arranged for the vertical slides ol very 
large machines, and an automatic lifting device prevents the 
heavy tools from dragging on the return stroke. 

Both heads may be operated together in either direction, 
making practically two independent planers. The driving 
mechanism is all brought to the front end of the cross-rail 
within easy reach of the operator, so that without moving from 
his position he can control the vertical and the horizontal 
motion of either head. 

Side heads are furnished, if desired, with most of the larger 
machines, but can be omitted if unnecessary' In general, 
planers having a capacity of 36 inches and upwards should 
have provision for attaching side heads when wanted. 

The side head has all the adjustments of the ordinary head, 
and an extra long slide is provided for use on overhanging 
work. 


8 . The Gearing for Table. 

There are two general methods of driving the table of 
the machine back and forth, viz., the spur-geared drive 
and the spiral-geared drive. The former is by far the more 
common on the sizes of planers generally used in shops, and 
is too well known to need very much description. A rack 
running lengthwise on the under side of the table is driven by 
a large idle gear, usually called the bull wheel. This in turn 
is driven by a pinion on the countershaft, which latter is 
connected by another pair of gears to the driving shaft of 
the machine. This general arrangement can be seen in 
Fig. 1. 

In some machines the last set of gears are located outside 
the lied as shown in Fig. 5. Two pairs of gears are employed 
so that narrow, quick-running belts may be used on the 
driving pulleys. It would be difficult to shift wide, slow belts 


PLANING MACHINES 


15 


promptly at the ends of the stroke. The large idle gear has 
been used to bring the gearing down away from the table, and 
because the teeth on a large gear are stronger and have more 

O O O 

contact than those on a pinion. 

For modern planing machines using self-hardening steels 
and taking heavy cuts the gearing should be unusually strong 
and stiff. This is accomplished by using cut steel rack and 



gears and by having the journal boxes for the shafts inserted 
directly in holes bored in the sides of the bed casting. The 
shafts must be of large diameter and short between bearings, 
and the bearings themselves must be of good size and easily 
oiled. 

There are several modifications of the spur-geared drive, the 
most common being the substitution of bevel for spur gears 
next the driving pulleys. This arrangement brings the 
driving shaft parallel to the bed, and permits of the planer 





























































































16 


MODERN AMERICAN MACHINE TOOLS 


itself being placed with its line of stroke parallel to the over- i 
head shafting. There is also some saving of width by this 
change. 

The Whitcomb Manufacturing Co. substitutes a belt drive 
for one pair of gears and does away with the ‘ bull wheel.’ 
Fig. 9 is taken from the catalogue of this company and shows 
the whole arrangement plainly. The makers claim for this 
drive several advantages, among which are comparative still¬ 
ness and smoothness of action and the possibility of much 



Whitcomb Manufacturing Co., Worcester, Mass. 


higher cutting and return speeds than would be advisable 
with gears. 

On large planers it is still necessary to use the ‘ bull wheel ’ 
in order to bring the second gear low enough to permit of the 
use of side heads. 

The spiral-geared drive, originally introduced by the 
Sellers Company of Philadelphia, is used as a rule only on 
the larger sizes of planers. The usual arrangement may be 
seen in Fig. 8, which shows a plan view of the drive as 
applied to a widened planer. As may be seen in the cut, the 
rack is driven by means of a special pinion located on an 
oblique countershaft. This shaft is driven directly from the 
main pulley-shaft through a bevel gear and pinion. This 




















































PLANING MACHINES 


17 


system brings the pulley-shaft in line with the stroke of the 
machine and permits the planer to be located with its length 
parallel to the overhead shaft; sometimes this is a distinct 
advantage. 

The spiral pinion has a much larger number of teeth in 
contact with the rack than the spur gear (eight in the 
machine shown), giving greater strength and more smoothness 
i in action. The simplicity of the spiral-geared drive is an 
4 argument in its favour. Actual use has shown it to give 
remarkable smoothness of action and a freedom from shock at 
reversals, accompanied by uniformity in length of stroke. 


9. The Reversing Gear. 

The general method of reversing the motion of the table is 
the same in all planers. Adjustable dogs or stops on the sides 
of the table engage a system of levers in such a manner as to 
shift the belts on the driving pulleys at either end of the 
stroke. One of the vertical driving belts is open and the other 
crossed, and each is provided with a tight and loose pulley. 
A shipper rod or lever is used for each belt as shown in Fig. 5. 
The details of the mechanism vary considerably in the differ¬ 
ent makes of planer, but consist for the most part of a cam 
plate with two rolls to actuate the shippers and a link 
connecting this cam to the shifter lever, tins latter being 
pushed alternately forward and back by the dogs on the 
li table. Figs. 1 and 5 show this quite plainly. The difference 
in speed between forward and return strokes is generally 
obtained by using pmlleys of different size for the two 

oj belts. 

One of the most annoying features of the older machines 
was the squealing of the belts at the instant of reveisal, 
caused by the belts being moved simultaneously, one belt 
not leaving the fixed pulley until the other was paitly on. 
This is done away with in the modern machines by the use 
of the cams, which move off one belt before moving on the 


If 








18 


MODERN AMERICAN MACHINE TOOLS 


other. High speed and rather narrow belts are employed, as 
these can be more quickly shifted. In some machines the 
driving pulleys are located on opposite sides of the bed. The 
shifter lever is provided with a handle so that it may be 
operated by hand in setting work. There should be such a 
handle on each side of the machine. (See Fig. 6.) 

It should also be possible to run the table entirely out from 
under the housings, without disturbing the dogs, when it is 
necessary to measure or examine the work. 

The dogs on the table are usually provided with handles so 
that a wrench is unnecessary. 

Some machines are fitted with a locking device in the 
shipper, so that it may be fastened with both belts on loose 
pulleys, and thus prevent accidents from starting up of the 

io. The Feed Mechanism. 



The most usual device for operating the feed screws of the 
cutter head is a vertical rack, which moves up and down on 
the front side of the housing and actuates a train of gears by 
means of a ratchet motion. In Fig. 5 this rack can be seen 
v r ith the reciprocating device at the bottom and the adjusting 
screw for changing the length of stroke. , 

In nearly all the illustrations a similar device is shown 
with some modification. (See Fig. 1.) 

In the planers illustrated by h ig. 2 a splined vertical 
shaft oscillating in a horizontal circle communicates motion to 
the feed gears. 

hither of these contrivances permits of a vertical adjust¬ 
ment of the cross-rail without disturbing the feed. ( 

Wheie two heads aie used each should have its vertical 


and horizontal feeds independent of the other, and it should 
be possible to feed at either end of the stroke. The side, 
heads, if any, should also have power feeds independent 

of the other. All feeds should be adjustable when machine 
is in motion or at rest. 


PLANING MACHINES 


19 


II. Widened Planers. 

In a large establishment doing a great variety of* work it 
is usually better policy to use standard machines of such 
different capacities as to accommodate any job that may come 
in. This because standard sizes of machines are designed as to 
strength and as to convenience in operation for certain sizes of 
work and will do that work better and more cheaply than any 
other machines. 

On the other hand, it frequently happens that in a smaller 
establishment having a limited number of machines, work has 
to be rejected or done at a great disadvantage because it is 
slightly larger than the maximum capacity of planers or of 
lathes. 

This state of affairs is an excuse for the widened planer and 
the gap lathe, and under such circumstances they will often 
repay a good interest on the investment. Fig. G has already 
been referred to as an illustration of a widened planer. This 
particular machine planes 38 inches in height, and has been 
widened by bolting the rear housing to a projecting cheek on 
the bed so as to plane 60 inches in width. The top brace and 
cross-rail being larger than the standard pattern, have deeper 
1 and stronger bracing on the back. The machine is then 
practically as strong as the standard 38-inch planer, and at 
the same time can plane the extra width mentioned. 

It would be unreasonable to expect it to be capable of doing 
as heavy work as the regular 60-inch machine, but it can take 
the place of such a machine in emergencies. The planer 
shown in the cut has a supplementary table or slide in the 
rear of the main table which can be used to support heavy 
work. 

Fig. 7 also shows a widened planer, the increase in width 
being but slight as it planes 48 inches in height and 60 
inches in width. The increase of six inches on a side is 
obtained by widening the bed at the housings without chang¬ 
ing the general design of the machine. Such a planer 




20 


MODERN AMERICAN MACHINE TOOLS 


would be nearly, if not quite, as strong as the standard 
machine, and would take the place of a 60-inch tool on wide 
work. 

12. Open-Side Planers. 

The so-called open-side planer, as its name implies, is a 
planing machine which has one side open for large work, one 
housing being entirely removed and the cross-rail depending 
for its support upon rigid bracing to the remaining upright. 
Fig. 10 illustrates this type of machine as built by the Detrick 
and Harvey Machine Co. of Baltimore, Md., the leading manu¬ 
facturers of open-side planers in the United States. 

The construction of the bed, table reversing gear and feed 
mechanism of these machines does not differ materially from 
that of ordinary planers. 

As shown in the figure, very wide V’s are used on this 
particular machine and special covers are provided to protect 
the ways from chips and dirt. The Sellers spiral gear drive 
is employed for moving the table, the large bevel gear show¬ 
ing plainly in the illustration. 

The post or housing is made unusually deep, is braced 
laterally by projecting box flanges, and is tongued and 
grooved as well as bolted to the bed. It is readily seen that- 
this member is exposed to a severe torsional stress from the 
pressure of the cutting tool and must be designed accord¬ 
ingly. 

The cross-rail also, having no support at the rear end, is 
now in the condition of a bracket fixed at one end, and must 
be well braced. This is accomplished by a diagonal brace, as 
shown in the cut, bolted to the cross-rail and to the housing. 
A slide is provided on the housing for the end of the brace, 
to allow for vertical adjustment, but when the planer is 
cutting the brace is firmly clamped to the slide. 

To still further stiffen the cross-rail it has a vertical 
projection running down the front of the housing and so 
arranged as to permit of clamping the two together when the 










PLANING MACHINES 


21 


machine is in operation. This construction prevents the 
cross-rail from springing upward under a heavy cut and 



Fig. 10. 

OPEN-SIDE PLANER—REAR VIEW. 


The Detrick and Harvey Machine Co., Baltimore, Md. 


makes the rail and housing practically one piece 


A side- 












22 MODERN AMERICAN MACHINE TOOLS 

head is mounted on a slide attached to this vertical leg and 
can be operated independently. 

All the cutting heads have the same adjustments and 
feeds as on an ordinary planer, and the manipulation of the 
machine is much the same. 

Each manufacturer must decide lor himself whether it will 
pay him to use a machine of this kind. On one hand it may 
be said that the open-side planer is not so still and con¬ 
sequently will not take so heavy a cut without chattering as 
a standard planer of the same size. On the other hand, it is 
possible to do work on a machine ot this class that could not 
be done at all on a standard planer of any reasonable 
capacity. Open-side planing machines have been found 
particularly well adapted to planing limited areas on large 
pieces, such as the junction areas ot engine and machine 
frames and the joints in structural steel work. In this line, 
however, they have to contend with a notable rival, the 
so-called rotary planer of which more will be said in another 
place. 

13. Combination Planers. 

In establishments where the use of an open-side planer 
would be the exception rather than the rule, and such a 
machine could onlv be regarded as an emergency tool, a com¬ 
promise is sometimes adopted. The Detrick and Harvey Co. 
build a planer which can be used with two housings or with 
one as conditions demand. The cross-rail is made of extra 
length, projecting several feet beyond the diagonal brace 
and supported at the rear end by an adjustable housing. 
The latter can be adjusted on its bed for ditferent widths of 
cut and then clamped rigidly in position. 

If the work is extraordinarily wide this housing can be 
entirely removed, the extension cross-rail can be slid back, 
and there remains an open-side planer. The unusual weight 
of cross-rail, braces, etc., in open-side and combination 
machines makes it necessary to give special attention to the 








PLANING MACHINES 


d | question ot counter-balancing and power elevation for these 
I parts. 


1 


Lhe supplementary guide, which is a necessary feature of 



Fig. Jl. 

COMBINATION PLANER. 

The Mark Flather Planer Co., Nashua, N.H. 

extension planers of any type, usually consists of an I-beam 
supporting a train of rollers and a rail which is carried in 
turn by the latter. This rolling table, as it is called, can be 
moved to and from the planer, and forms an additional 
support for very wide and heavy work. 











24 MODERN AMERICAN MACHINE TOOLS 

Fig. 11 shows a combination planer as built by the Mark 
Flather Planer Co. of Nashua, N.H. The illustration 
shows a standard planer converted into a partially open-side 
machine by running the rear housing back on the bed and 
interposing a stiff box casting between it and the cross¬ 
rail. 

As will be seen from the cut, the top brace is made of such 
a form as to support the top of housing in either position. A 
supplementary vertical leg is used to assist in holding up the 
outer end of cross-rail and by an ingenious combination of 
bevel gears and telescoped shafts the same power-elevating 
mechanism is available in either position of the housing. 

A 42-inch standard planer is so changed by this device as 
to plane a horizontal area of over 5 ft. each way on a piece of 
any width. 




14. Cutting Speeds. 


Table I. 1 shows the cutting speeds in feet per minute as 
recommended by various manufacturers. These vary from 15 
feet per minute with the larger machines to 22 feet perl 
minute with the smaller. 

TABLE I \ 


Cutting Speed in Feet per Minute. 


Name of Maker. 



Size of Macl 

ine ia 

Inches. 


24 

30 

36 

42 

48 

60 

72 

Detrick and Harvey, 


20 

18 

174 

16 

16 

15 

Flather, .... 


20 

20 

18“ 




Grajr, .... 

... 

99 

«J 

22 


20 



Pond, .... 

• . • 

. . . 

14 

... 

18 

Actual Test 

Flather (recommended), . 


30 

27 

25 

25 

23 

99 1 _ 

Gray, .... 

66 

Actual Test 



[High Speed 

American Tool Works, 

60 

5 > 


51 



j Steels. 


1 See Machinery, New York, July 1903. 


























PLANING MACHINES 


25 


In general, cutting speeds are higher in the United States 
than in Great Britain or Germany, for all classes of machine 
tools. It is not unusual to find lathes cutting cast iron at a 
speed of 40 feet per minute. 1 

With the introduction of air-hardening steels there has 
been an increase of from one to two hundred per cent, in the 
speeds attained by lathes when cutting wrought iron or mild 
steel. It has been found possible to run continuously on 
work of this kind at a speed of 160 feet per minute. No 
such increase has been found practicable with planing 
machines on account of the intermittent nature of the cutting 
and the shock due to reversal. Neither the cutting tool nor 
the planer itself seems able to stand the sudden changes at 
such high speed. One firm of American planer manufacturers 
report that they are using speeds of from 35 to 40 feet per 
minute with small machines, and 28 feet per minute with 
| larger size (42-inch). They do not, however, recommend 
speeds as high as these, taking into consideration the probable 
expense for repairs. As a result of their experience they 
recommend for air-hardening steel tools a speed of about 30 
feet per minute when used in machines 30 inches and under, 
and from 25 to 27 feet per minute up to 48 inches. Above 
this latter size the speed should be reduced to 22 or 23 feet 
per minute. 

The speed of return on American planers is from three 
to four times the cutting speed, being less on the larger 
machines. 


15. Horse-Power. 

The more extended use of the motor drive on machine tools 
has made it possible to determine conveniently and accurately 
the amount of power absorbed by the machine when cutting 
and when running light. 

Perhaps the first tests of this kind reported were those 

1 See Machinery , New York, July 1903. 











26 


MODERN AMERICAN MACHINE TOOLS 


made at the Baldwin Locomotive Works in 1896 and 
published in the American Machinist of that year. Table II. 
gives a summary of the results for such planing machines as 
were tested. 

The figures given for running the machines empty do not 
include the horse-power at the instant of reversal, but only' 
the average horse-power required to run the empty table 
forward and back. 

The power consumed by a 24-inch planer with 6-foot 
table as tested by the writer at various times averages about 
1 horse-power, with a maximum of 1 k horse-power. The 
amount of cast iron removed in the latter case was 25 
pounds per hour. A 48-inch Pond planer running on regular 
work in a shop was found to consume 5*6 horse-power in 
cutting and 11*4 horse-power at the reversal when cutting 
about 15 pounds of cast steel per hour. A 36-inch machine j 
of the same make required 4’3 horse-power when removing: 
about 7'5 pounds of cast steel per hour. These planers were 
equipped with electric motors of 20 and 15 horse-power 
respectively. 


TABLE II 

Horse-Power of Planing Machines. 






Horse-Power 

Total Cutting. 

Name of 

Size. 

Material 

No. of 


>> s’ 




Makers. 

Cut. 

Tools. 

, ^ 

Q . ^ 

Min. 






o 5 

£ 2 

Max. 

Avge. 





C C£> 














Sellers, 

62 in. x 35 ft. 

AVrt, Iron 

2 

4*4 

11-4 

20-6 

21-6 

21T 


62 in. x 35 ft. 

55 55 

9 

-J 

• • • 

5*8 

23 0 

26-0 

24-5 

Bement, . 

24 in. x 13 ft. 

Steel, 

2 

1-95 

4*3 



8-0 

Sellers, 

36 in. x 18 ft. 

Wrt. Iron 

9 

3-2 

4-3 



16-7 

55 

56 in. x 35 ft. 

5 5 5 5 

2 

4-6 

9-9 

130 

13-7 

13*3 

5? 

56 in. X 24 ft. 

5 5 5 5 

9 

— 1 

4-56 

6-0 

160 

17-7 

16 8 

JNot given 

36 in. X 12 ft. 


2 

2-7 

3-0 

11-3 

13-8 

12-5 

























PLANING MACHINES 


27 


lable III. is compiled from results published by Machinery , 
New York, in 1902. 

TABLE III 

Horse-Power of Planing Machines. 


Size of Machine. 

Material cut. 

Cutting Speed. 
Ft. per rain. 

_ 

Number of 
Tools. 

u 

o 

o 

«—J 

4-1 

O 

EEorse-Power. 

CSj r-> 

c ^ 

'S ' t 

O : 

Reverse. 

10x10x20 ft., . . 

Cast iron, 

18 

3 

30 

26 5 

23-6 

42-9 

8x8x20 ft., . . . 


18 

3 

25 

16-0 

14*8 

28-2 

GO in. x 60 in. x 12 ft., 

Steel casting, 

21 

9 

-J 


100 

14-0 

16-0 

28 in. x 52 in. x 6 ft.,. 

Cast Iron, 

9 9 

— - — 

1 

3 

3T 

3-8 

4-4 

36 in. x 36 in. x 12 ft., 

Cast Steel, . 

17 

2 


2T5 

2*22 

110 

36 in. x 36 in. x 12 ft., 


9 9 

mJ +J 

9 


2 85 

3 06 

110 

72 in. x 72 in., . . . 

Cast Iron, 

35 

9 

-J 

30 

18-3 

7-3 

70-7 


16. Electric Drives. 

The driving of machine tools by electricity is a subject 
which will be discussed in a separate chapter, but some of the 
special modifications of motor driving for planing machines 
will be considered now. 

If several machines of small or moderate size can be 
arranged in a group, the most economical method is to drive 
them all from one countershaft. One motor of a size some¬ 
what less than the aggregate horse-power of the planers can 
be used to drive this shaft directly. This arrangement 
makes the first cost considerably less than for separate 
motors. The countershaft running at the same speed as the 
motor acts as a fly-wheel to furnish the excess of power 
needed at reversal; in fact, it is well to have a small flv- 
wheel on the counter to assist in the regulation. 

Planing machines of 36-inches capacity and upwards re¬ 
quiring motors of more than 5 horse-power can best be 
driven by separate motors. In arranging a planer for the 
electric drive it is usual to mount the countershaft on brackets 























Fig. 12. 

PLANER WITH ELECTRIC DRIVE AND BELT CONNECTION. 


The G. A. Gray Co., Cincinnati, Ohio. 





PLANING MACHINES 


29 


projecting from the top of the housing as shown in Figs. 12 
and 1 3. Connection between the countershaft and motor is 
then established either directly or through gears, belts or 
silent chain. 

The motor may be located on a bracket forming a part of 
the machine, and thus the whole be self-contained as is the 
case in Fig. 13 ; or the motor may be hung from the ceiling 
or bolted to the floor. Fig. 12 shows a very neat adaptation 
of the latter plan. The objection to the direct mounting of 
the armature on the countershaft is the necessity for using an 
expensive slow-speed motor. 

Fig. 13 illustrates the application of the chain-drive to a 
planer, thus making the machine self-contained, and at the 
same time doing away with the slow-speed motor. 

The Cincinnati Planer Co. have introduced a system of 
speed control for motor-driven planers whereby the cutting 
speed can be varied while the return speed remains un¬ 
changed. 

A constant speed motor is bolted to a bracket on top of 
the housings and is geared direct to a countershaft, which in 
turn is bolted to the return motion. A second countershaft 
is used to drive the forward or cutting motion, and is geared 
to the first by a train which can be varied at will without 
stopping the machine. For example, the cutting speeds on 
one of their machines are 20, 25, 30 and 38 feet per minute, 
while the return speed is constant at 72 feet. The higher 
cutting speeds will be found particularly useful when employ¬ 
ing air-hardening cutting: tools on wrought iron or soft steel. 

Mention should also be made of the reversing motor 
system of control introduced by the Electric Controller and 
Supply Co. of Cleveland, Ohio, which does away with belts 
entirely. 1 

The G. A. Gray Co. of Cincinnati recommend the following 
horse-powers of motors for planing machines under average 
conditions. 

1 See Cassier’s Magazine, June 1905. 
























PLANING MACHINES 


31 



Standar 

d Spur-Geared 

Planers. 



Size, 

• • 

22" 24" 26" 

28" 

30" 

32" 

36 

H.P. 

of Motor, 

24 34 34 

4 

5 

6 

6 

Size, 

• , 

36" Hvy. 

42" 

48" 

56" 

72 

H.P. 

of motor, 

8 

12 

15 

15 

25 


The powers of some motors in actual use on planers are as 
follows :— 


30 in. x8 ft. Woodward and Powell, . 
36 in. X12 ft. ,, ,, 

56 in. x 12 ft. Gray Co. 

24 in. x 6 ft. Pond Co. 

36 in. X10 ft. ,, ,, . 

60 in. x 25 ft. ,, ,, . 


10 H.P. 
15 

20 


3) 


0 


3 3 


0 


15 


5 > 

>5 


This shows some variation in the size of motors furnished for 
the same size of planer, due probably to a difference in the 
conditions. The motor should have an excess of power over 
that required for ordinary cutting on account of the ‘ kick ' at 
reversal. 










CHAPTER II 


CRANK PLANERS, SHAPERS, AND SLOTTING MACHINES 

17. Crank Planers. 

As was noted in Chapter I., the distinction between planers 
and shapers is that of moving the work against the cutting 
tool or moving the tool against the work. Crank planers 
belong to the former class, but as they are in size and 
character of work more like shapers they will be considered 
in this chapter. Fig. 14 illustrates this class of machine, 
which, as compared with standard planing machines, is 
characterised by high speed and a short stroke. The 
machine shown in the cut has a capacity of 17 x 17 inches, 
while the maximum travel of the table is only 12 inches. 

As its name implies, the crank planer takes the motion of 
its table from a crank instead of from a rack and pinion. 
The motion used is generally the Whitworth quick return or 
some modification of it, and the stroke is adjustable from zero 
to the maximum. The crank planing machine has this 
advantage over the standard machine, that the stroke is 
definite and exact and it is possible to plane right up to a 
mark without danger of over-running. It is somewhat stiffer 
and more accurate than a shaper on account of the table 
being supported its whole length. 

Its accuracy and speed make it an excellent machine for 
tool and jig work. 

The general arrangement is so much like that of the 
standard machine as to require no detailed description. 

32 


SHAPING MACHINES 


33 



Shaping Machines. 


Nearly all shaping machines are pillar shapers, so-called ; 
that is, the mechanism is all supported by one pillar or column 



CRANK PLANER, 17 x 17 x 12 INCHES. 


Whitcomb Manufacturing Co., Worcester Mass. 

standing on a broad base. The principal elements of such a 
i machine are : (a) the column above referred to, which carries all 
the moving or adjustable parts ; (b) the ram or horizontal slide 

c 
























34 


MODERN AMERICAN MACHINE TOOLS 


for carrying the tool head ; (c) the tool head itself; ( d ) the 
cross-rail which is adjusted vertically on the front of column 
and which in turn carries the table ; (e) the table which holds 
the work and is fed horizontally on the cross-rail; ( /) the 
gearing for driving the ram; (g) the feed mechanism for 
operating the table. 

To these might be added that almost indispensable adjunct 
the vice, by which nine-tenths of all the work on a shaper is 
held. 


19. The Column. 

As may be seen by reference to the various illustrations in 
this chapter, the column of the shaping machine is a plain, 
rectangular cabinet with a broad base provided with tool 
shelves and with a closet for miscellaneous fittings. 

The front of the column is provided with rectangular,, 
vertical ways to which is clamped the cross-rail by means of 
gibbed slides. The top of the column carries gibbed ways 
for the horizontal slide of the ram. Various bosses and 
bushings support the running gear of the machine. 

The cabinet form is particularly well adapted for shaper 
columns, and in fact for frames of all compact, self-contained 
machines. It is stiff to resist bending and twisting moments, 
and it is stable on the floor or the foundation. 

It is of a convenient shape for the attachment of the 
vertical and horizontal slides, and the interior forms a safe and 
convenient location for the reciprocating mechanism. 

The base should project enough to give stability, but not 
enough to interfere with the standing room of the operator. 
The front of the base usually projects more than the sides, 
and is planed true to permit of blocking up the table when 
heavy work is being machined, as shown in Fig. 15. This pro¬ 
jection may be furnished with T slots as illustrated in Fig. 16, 
so that the table may be removed and large work bolted 
directly to the bed. As may be seen in these illustrations, 







SHAPING MACHINES 35 

the cabinet has an opening directly beneath the ram so as to 
permit the splining of long pieces of shafting. 


Fig. 15. 

GEARED SHAPER. 

The John Step toe Shaper Co., Cincinnati, Ohio. 


20. The Ram. 

This is the working element of* the machine, and on its 
strength and accuracy depends the value of the shaper as a 
machine tool. 








MODERN AMERICAN MACHINE TOOLS 


36 

As may be seen in the various illustrations, a hollow cylinder 
forms the basis of the design of the ram in modern shaping 
machines. In its ability to resist both torsional and bending 
strains this structure has no rival. The cylinder is more or 
less open on the under side to receive the driving elements, 
and is fitted with two rectangular wings running the whole 
length to serve as slides. 

To do accurate work the ram must not only be strong in 
itself but must have long and wide bearing on the column. 

and 

not dove-tailed, and must be so gibbed as to be capable of 
adjustment. 

In some machines the ways project over the table to afford I 
additional support in cutting. 

In so far as this can be done without interfering with the 
location of work on the table, it is a good feature. 

The ram is driven either by some form of crank motion 
having a quick return, in which case the machine is called a 
crank shaper, or by a rack and gear like the table of a planer, , 
being then called a geared shaper. 

When the crank motion is used it is necessary to adjust 
the ram forward and back on the driving mechanism so as to 
locate either terminal of the stroke. Some shapers are so 
arranged that this can be done when the machine is run¬ 
ning. See, for instance, Fig. 16, where the hand-wheel and 
locking lever on top of the ram are a part of this adjustment. 
The exact length of stroke is sometimes shown by a pointer 
and scale on crank machines. 

2i. The Tool Head. 

This element does not need any detailed description, being 
essentially the same as on a planer save that it has no 
horizontal feed motion. Like the planer head it can be 
swivelled to plane at any angle, and can be fed vertically by a 
screw and hand crank. In a few cases the head has a power 


The ways in which the slides move must be rectangular 









Fig. 16. 

24-INCH SHAPER, WITH TILTING BOX-TABLE. 

"he Mark Flather Planer Co., Nashua. 
















38 


MODERN AMERICAN MACHINE TOOLS 

feed as may be seen in Figs. 16 and 17. In the latter 
machine there is combined with the power feed an automatic 
stop which makes it safe to leave the machine running. 

„ 22. The Cross-Rail. 

The rail is attached by rectangular gibbed sides to the 
vertical ways on the front of the column, can be adjusted at will 
and then clamped rigidly in position. The larger machines 
frequently have a power attachment for raising and lowering 
the rail such as shown in Fig. 17. 

O 

The machine illustrated in this latter figure has also an 
unusually wide bearing surface on the front of the rail giving a ; 
firm support to the table. The combination of rectangular and 
dove-tail ways serves the same purpose as in the cross-rail of' 
a planer. 

The cross-feed screw is also similar to that of a planing 
machine and is operated by means of a ratchet and pawl. 


23. The Table. 


A box-shaped casting, planed accurately square and fitted 
with T-slots on top and sides, serves to hold the work. This 
table is sometimes attached directlv to the cross-rail as in 
Fig. 17, but is usually bolted to an apron or saddle which 
slides on the rail. The table can then be removed and work 
clamped directly to the apron when necessary. 

The most serious fault of the shaping machine is the over¬ 
hang of the table without adequate support, which permits of 
more or less springing under the pressure of the cutting tool. 
This, added to the upward spring of the overhanging ram, 
results in untrue work. 

To remedy this difficulty additional supports are sometimes 
used. Fig. 16 shows a bracket underneath the table with an 
adjustable support for the outer edge of the latter. The 
bracket is attached to the cross-rail and rises or falls with it. 











> 

►—I 

03 

/-s 

O 

•—i 

o3 

H 

O 

W 

J 

y 

H 

pq 




77te Potter and Johnston Machine Co., Pawtucket, R.I. 








40 MODERN AMERICAN MACHINE TOOLS 

The planed surface on the base underneath the table as seen 
in Figs. 15 and 16 may be made to serve a similar purpose. 

Some builders provide an adjustable step which may be 
bolted to the under side of the table, and which has on its 
lower end a roll to travel on the planed surface of the base. 

The ordinary motion of the table is the horizontal feed on 
the cross-rail. 

Some makers provide, however, a swivel adjustment to the 
table which permits of using the power feed on the cross-rail 
to do bevel or angular work instead of swivelling the head. 
Fig. 17 shows one of these tilting tables. 

24. The Driving Gear. 

As has been already stated, shaping machines may be put 
in two general classes, those driven by crank motions, and 
those driven by racks. 

These two kinds of drive have the same advantages and 
disadvantages as in planing machines. While most planers 
have a rack drive, and crank planers are the exception, the 
majority of shapers are driven by some sort of a crank motion. 
The most popular of these is the Whitworth ‘ quick return ’ 
in its various moditications. Fig. 18 shows this drive clearly, 
but in most machines it is concealed inside the column. 

The adjustment for short or long stroke is obtained by 
sliding the crank pin, which drives the ram, in a diametrical 
slot on the crank. This adjustment is made without stopping 
the machine by means of a screw and bevel gears. The great 
advantage of the crank motion is in its positive length of 
stroke, making it desirable for short work. Its disadvantages 
are two:— (l) That the time of a long stroke is just the same 
as that of a short one, giving high cutting speeds 011 long 
strokes and low speeds on short strokes. This makes it 
necessary to introduce the complication of cone pulleys, and 
on larger machines the further addition of back gearing. (2) 
That the cutting speed is not uniform, being that due to a 








ELECTRICALLY DRIVEN TRAVERSE SHAPER, 18 INCHES x 14 FEET 



















42 


MODERN AMERICAN MACHINE TOOLS 


crank movement, slow at the beginning and end, and fast in 
the middle. This defect has been overcome in some machines 
by introducing elliptic gearing in such a way that the irregu¬ 
larity of the gear motion neutralises that of the crank, 
producing a nearly uniform motion both on cut and return. 

Geared’ shapers so-called are driven by racks on the under 
side of the ram and a train of gears similar to those used on 
planing machines. In order to permit of a clear passage for 
shafts and other long work under the ram, two racks are 
generally used, one on either side of the slot in the column. 
The shipping device is also similar in character to those used 
on planers. Two adjustable dogs on the ram move the ship¬ 
ping lever to and fro, or this latter can be moved by hand 
when desirable. The shipping lever actuates a cam or 
equivalent device whereby the belts are shifted on the 
pulleys, one at a time. Fig. 15 gives a particularly clear 
view of this mechanism. 

The geared shaper labours under the same disadvantage as 
the planer in not having a positive length of stroke and in 
depending upon friction and inertia to control the motion. 

On the other hand it has perfectly uniform cutting and 
return speeds under all conditions, and either end of stroke 
can be quickly located w T hile the machine is running. 


25. The Feed Mechanism. 

In general, shapers have but one power feed, viz. the 
horizontal feed of the table. Since shaping machines are 
used mostly on small work and over small cutting areas, the 
necessity for power feed is not so apparent as on larger 
machines. 

Many manufacturers will furnish a power feed for the 
downward motion of the tool head when it is desired. The 
machines shown in Figs. 16 and 17 have such a feed mechan¬ 
ism operated by the reciprocation of the ram, while other 
makers offer to attach the like when the customer desires it. 


SHAPING MACHINES 


43 


The cross-feed consists of a reversible ratchet on the feed¬ 
screw driven by a link and adjustable crank motion, these 
features being common to nearly all the machines shown. 
This, like the other adjustments, can be changed while the 
machine is in operation. 


26. The Countershaft. 

Crank shapers are usually driven by the ordinary counter¬ 
shaft with tight and loose pulleys. Geared or rack shapers 
have in themselves no provision for varying the cutting speed, 
and on small work or on brass or composition castings this is 
sometimes a disadvantage. To remedy this such shapers are 
sometimes furnished with a variable speed countershaft, such 
that its speed can be changed at the will of the operator by 
merely moving a lever. 


27. Electric Driving. 

The same considerations would guide one in arranging 
electric transmission for shaping machines and for planers. 
Several small machines of one type can be best driven in a 
group from one countershaft and by one constant speed 
motor. 

When, however, it seems desirable to drive a shaper inde¬ 
pendently there are several combinations available. The 
most usual method for crank shapers is that illustrated in 
Fig. 17 , where a constant speed motor is attached to the base 
of the machine and belted to the driving shaft over cone 
pulleys. The figure shows one geared speed reduction 
between the driving shaft and the machines to permit of the 
use of a high-speed motor. Another method, rather more 
expensive but more convenient for the operator, is to use a 
variable speed motor belted direct to the lower driving shaft 
of the shaper and to depend on electric speed control. 


44 


MODERN AMERICAN MACHINE TOOLS 


A third method does away with belts entirely, employing 
a variable speed motor geared to the driving shaft. In this 
latter case, if the shaping machine is of the geared type, the 
motor may be used to reverse the machine as has already 
been explained in the case of planers. 

28. Traverse Machine. 

The traverse shaper is radically different from the standard 
machine in many of its details, whether it carries one or two 
heads. 

Strictly speaking, a traverse shaper is any shaper in which 
the cross feed operates the tool instead of the work. This 
change, however, usually entails others which differentiate 
the machine widely from the standard type. 

An examination of Fig. 18 shows these differences clearly. 
The simple cabinet is replaced by a wide, box-shaped bed 
carried on two or more supports. Rectangular ways run from 
side to side at the top, supporting wide saddles or carriages 
which are fed across and back by feed screws. 

These carriages support the rams and the entire recipro¬ 
cating mechanism, this mechanism being driven by a feed rod 
similar to that on a lathe. 

To the front of the bed are bolted the adjustable vertical 
ways which hold the tables. These can be located at will 
towards right or left of the machine, while the tables have 
the usual adjustments as in standard shapers. It is thus 
possible to locate the work at any part of the width of the 
machine and to operate on it with either head. Other attach¬ 
ments for holding work such as centres, cone mandrels, etc., 
can be fastened to the table or directly to the bed itself. 

The convenience of this machine for handling some kinds 
of work is apparent. It is in principle an open-side planer 
with a stationary table and travelling housing, and should 
be particularly useful in finishing spots on limited areas on 
comparatively long and unwieldy pieces. 


SHAPING MACHINES 


45 


29. Open-Side Shaper. 

One serious objection to the ordinary shaper is the over¬ 
hang of the ram in taking long cuts. To overcome this 
difficulty in a measure, one firm manufactures an open-side 
machine in which the ways are one above the other and 
extend for a considerable distance over the table. 1 The 
housing, as it is called by the makers, by reason of its shape 
and location, affords considerably more support to the ram 
than is usually the case. Thus in the machine described, 
when the tool is out to the end of a 24-inch stroke the end of 
the ram is flush with the end of the housing. The driving 
mechanism is of the gear and rack order. The table differs in 
a marked degree from the ordinary shaper table, being more 
like those used on milling machines. The apron is expanded 
into a bracket or knee, raised and lowered by a screw at some 
distance from the column, while the table is flat instead of 
box-shape and has a wide bearing 011 the knee. Contrary to 
the usual practice, the sLots in the table are transverse to the 
stroke. This seems the better way. 

It would seem that both the ram and the table in this 
machine would be stifter and more accurate than those 
ordinarily in use, especially on long cuts. 

30. Draw-Cut Shapers. 

The standard shaping machine when taking a cut tends to 
spring cross-rail, apron and table away from their several 
supports and to open all the joints. The draw-cut shaper 
shown in Fig. 19 removes this difficulty by pulling instead 
of pushing the cutting tool, thus bringing the table and 
its connections into compression rather than tension. This 
reversal of the motion of the ram has the further advantage 
of causing the tool to spring away from rather than towards 
the work, when cutting, on the principle of the spring tool. 

An abutment can be placed between the work and the 
1 The Fox Machine Co., Grand Rapids, Mich. 


46 


MODERN AMERICAN MACHINE TOOLS 

frame of the machine, so that the pressure exerted by the 
tool may be transmitted directly to the frame. 

The ram is driven by rack and gear, as may be seen from 

the figure. 



Fig. 19. 

MORTON DRAW-CUT SHAPING MACHINE. 

The Morton Manufacturing Co., Muskegon Heights, Mich. 


In criticism of this machine it may be said that the pulling 
action tends to spring open the joints in the tool head. The 
machine illustrated shows a complication of mechanism which 
would prejudice most buyers against it at first sight. A 
comparison of the illustration with those before referred to 
will make this clear. If the advantages of the draw cut could 







SLOTTING MACHINES 


47 

be obtained without so much additional mechanism the result 
would be more satisfactory. 



Fig. 20. 

10-INCH STROKE SLOTTER. 

New Haven Manufacturing Co., New Haven, Conn. 


31. Slotting Machines. 

A slotting machine may be described as a shaper with a 
vertical ram, the table remaining horizontal. Fig. 20 shows 
the ordinary type of frame and arrangement of parts for this 













48 


MODERN AMERICAN MACHINE TOOLS 


class of machines as built in the United States. Although of 
comparatively short stroke (usually ranging from 10 to 24 
inches), slotting machines are intended for heavy work, are 
back-geared and have frames capable of withstanding great 
pressures. 

As may be seen by reference to the cut, the frame is of a 
box-section and similar to the frame of an upright drill, but 
much heavier. 

The ram has a long bearing surface on the frame to prevent 
springing, and is counterbalanced by a lever and weight. It 
is driven by a crank and pitman and has two adjustments ; 
one is an adjustment of position to locate terminals of stroke ; 
the other an adjustment of the slotted crank to change the 
length of stroke. The crank is driven by the Whitworth 
quick return motion with a ratio of about 3 to 1. In Fig. 20 
the machine is driven by a cone of two steps with or without 
back gears. In other machines of this class it is driven 
directly by one large gear and a cone of four steps. The tool 
head is heavy and equipped with a double clamp tool-holder. 
The tool block must always have a relief motion for the return 
stroke. 

The pi line of the table being at riodit angles to the cutting 

I O O O D 

motion, it is possible to secure circular as well as straight 
feeds. 

Accordingly the tables of slotting machines have three 
power feeds, longitudinal, transverse, and rotary. 

The platen of the machine moves longitudinally on the 
frame, the saddle or cross-slide moves transversely on the 
platen, and the circular table can rotate on the cross-slide. 
Any one of these parts can be clamped rigidly to its neigh¬ 
bour, and by a combination of any two of the motions oblique 
or irregular outlines may be cut. 

The very general use of the slotting machine for finishing 
the profiles of irregular castings necessitates this entire 
freedom of movement in the table, and also demands great 
strength and rigidity of construction. 


SLOTTING MACHINES 


49 


The illustration shows plainly how well these requirements 
have been met. The details of the feed mechanism are 
so clearly indicated in the cut as to call for no special 
description. 

The convenience of these machines in operation is enhanced 
by the fact that all the adjustments are within easy reach of 
the operator when standing in one position. 

The range for various sizes of work is usually proportional 
to the stroke of machine. The diameter of table is from two 
to three times the stroke, while the maximum diameter of 
work is from four to six times the stroke. 

32. Key-Seating Machines. 

Machines which are specially designed for cutting the 
inside rather than the outside surface of the work belong 
to a different class and may be grouped under the above 
head. 

Although most generally used for splining the bores of 
wheels, gears, and cranks, they may be applied to any inside 
work with success. 

Fig. 21 illustrates a so-called draw-stroke slotting machine 
which belongs to this class. On account of the limitations 
of the work the design differs materially from that of the 
ordinary machine. 

The fact that the tool must work inside holes of a certain 
diameter precludes the use of a large ram, and a cylindrical 
(cutter bar is substituted which reciprocates vertically through 
a hole in the table. 

This slenderness of the bar makes necessary the upper 
bearing and the radial arm shown m the illustration. 

The pulling or draw-stroke is used in this class of machines 
to prevent springing and chattering of the cutter bar. 

This stroke is applied to large machines and possesses the 
advantages which have been discussed under the head of 
draw-stroke shapers. The cutter bar has a uniform cutting 

P 







50 


MODERN AMERICAN MACHINE TOOLS 


motion with a quick return, and an automatic movement oi 
the table relieves the cutter on the up-stroke. The table has 


t! 



Fig. 21. 

LARGE DRAW-STROKE SLOTTING MACHINE. 

Baker Brothers, Toledo, Ohio. 


the same motions as in the ordinary machine, and all feeds 
can be made automatic if desired. 


33. Rotary Planing Machines. 

Machines in which rotating cutters take the place of 
reciprocating or stationary tools belong to the milling machine 














SLOTTING MACHINES 


51 


division rather than to that of planing machines and will be 
treated in a separate chapter. There are, however, certain 
■ rotary planing and slabbing machines which occupy so 
directly the same field as planing machines as to demand 
attention in this chapter. 

The first of these is the so-called rotary planer as illustrated 
in Fig. 22. This machine is essentially a large traverse 
shaper (see Fig. 18) with the reciprocating ram and tool head 



Fig. 


22 . 


ROTARY PLANING MACHINE : HEAD 36-INCH DIAMETER. 

Wm. Sellers and Co., Philadelphia, Pa. 

replaced by a rotating disc of large diameter equipped with 
inserted cutters. 

This revolving tool-head is carried on a saddle which travels 
on ways and is driven by a power feed. The table of the 
machine has a transverse adjustment for setting the work. In 
some cases the entire machine is mounted on a turn-table 
and can be rotated to any point of the compass, the driving 
shaft being so connected to the machine by bevel gears as to 
permit this. As the machines are usually constructed, only 
the face of the tool head is fitted with cutters, and the machine 
is intended for vertical surfacing alone. 1 his planer is especi¬ 
ally well adapted for surfacing the ends and joints of large 















52 


MODERN AMERICAN MACHINE TOOLS 


structural pieces such as the members of bridges, cranes, hoists, 
etc., and possesses a rigidity which ensures accurate work. 
It is extremely difficult to do such on the ordinary planer or 
shaper on account of the springing and wear of the tool. 

Here the solitary cutting tool is replaced by forty or fifty, 
each one short and firmly supported. 

The machine, however, possesses no adaptability and can 
only be regarded as a special tool. 

34. Heavy Milling Machines. 

There is manufactured in this country a type of milling \ 
machine which so much resembles the planing machine in its 
frame construction and in its various adjustments and feeds 
as to entitle it to be considered in this connection. This type 
is sometimes known as the Ingersoll Milling Machine because 
the Ingersoll Company of Rockford, Illinois, makes a specialty 
of its manufacture. 

The building of these machines is not, however, confined to 
this one company. 

Fig. 23 shows a 36-inch machine of the planer type. The 
resemblance to the planing machine in most of the details is 
noticeable. In fact the bed, the table, the housings, the top- 
brace are so much like those of the planer as to need but little 
description. The travel of the table is so slow and so slight 
compared with that of a planer table that some changes are \ 
necessary. The ways are now flat instead of Y-shaped, and * 
either angular or square-gibbed slides are used, like those on 
a shaping machine. (See Figs. 23 and 24.) The table in 
Fig. 23 is in some respects more like that of a milling machine 
in the arrangement of the slots and the surrounding pan for 
chips. No reciprocating motion in the strict sense is needed, 
but a quick return by power is provided. Instead of cutting 
speeds of 20 and 25 feet per minute a travel of 2 or 3 feet per 
minute is a maximum, and very much less than this is of 
course the rule, 










The Hess Machine Co., Philadelphia, Pa. 

















54 


MODERN AMERICAN MACHINE TOOLS 


The housings, the top-brace, and the ways for the cross-rail 
and side-heads do not differ from those of an ordinary planing 
machine and need no additional description. 

Fig. 23 represents a machine equipped for horizontal work 
alone, while that shown in Fig. 24 has both top and side 
heads and can do any work that can be done by the standard 
planer. 

In the former case, the face of the cross-rail is tipped to 
an angle of 45 degrees to bring the milling spindle in a sym¬ 
metrical position with respect to the rail, and thus afford the 
most room for swinging the cutters. 

The massive construction of the cross-rail will be noted ; 
the necessity for this is apparent when we consider that the 
makers guarantee for a 42-inch machine the removal of 210 
cubic inches or 54 pounds of ordinary cast-iron per minute. 
This means a cut 42 inches wide and J-inch deep at the rate 
of 10 inches per minute. 

With the 36-inch machine shown in Fig*. 23 the makers 
guarantee a|--inch cut the full width of the machine and 8 
feet long in 30 minutes or 57*6 cubic inches of cast iron per 
minute. No planing machine could approach these figures. 

To give some idea of the stresses in these machines, it may 
be noted that the maximum pressure at the surface of a 
6-inch cutter on the 36-incli machine is given as 52,000 
pounds. On the other hand, it must be remembered that the 
pressure is steady, and that the shocks incident to reciproca¬ 
tion are absent. 

Fig. 24 represents a machine equipped for general work, 
there being two cutter-heads on the cross-rail and two side- 
heads. These heads have the same automatic feeds and the 
same adjustments as those in the ordinary type of planing 
machine. Each head carries a rotating spindle for the attach¬ 
ment of cutters, and can be used separately or in combination 
with its mates. 

The rotary motion is imparted either by spur gears or 
by worms and wheels, necessitating of course considerable 







SLOTTING MACHINES 55 

il complication and expense as compared with the standard 
g: planer. 

| the milling machine of this type can, however, do more 

t 



Fig. 24. 

48-INCH FOUR-HEAD MILLING MACHINE. 


The Tngersoll Milling Machine Co., Roclford, III. 


work than the planing machine and can do more kinds of 
work, cutting into and under projections where the planer 
would he at fault. 

Tools with inserted cutters are the rule in heavy milling. 

A face mill of this description 18 or 20 inches in diameter 





















5G MODERN AMERICAN MACHINE TOOLS 

can remove in a roughing cut 3G cubic inches of iron per 
minute. 

The inserted teeth can be made of ordinary tool steel or of 
air-hardening’ steel as may be desired. 

There are various modifications of the heavy milling 
machines as there are of the planer, such as widened, 
machines, open-side machines, etc. Machines are also made 
which are intended solely for vertical work or for special 
forms. The variety of work which can be done on a milling 
machine is probably greater than can be expected of any 
other machine in the shop. 

35. Miscellaneous Machines. 


This chapter and the preceding one treat of machines for 
producing flat surfaces, exclusive of grinding machinery, which 
will be treated in a chapter by itself. 

Planing, shaping and milling machines with their modifica¬ 
tions have so far been considered, and these form a large 
majority. The remaining machines in this class may rather 
be considered as special machines and not of so much general 
interest. 

Mention might be made of plate-planing machines for 
straightening and bevelling the edges of plates preparatory 
to riveting and calking. These are in principle large traverse 
shapers with special attachment for holding the plates. 

Also of vertical planing machines, where the housings are 
parallel to the table and the cross-rail stands in a vertical 
position. This arrangement makes the machine particularly 
well adapted for taking side-cuts, that is, for planing vertical 
instead of horizontal surfaces. 

While such machines are valuable for special work they 
would have no place in the ordinary run of machine shops, 
since they are too expensive to be allowed to stand idle. 

Considering in general machines for cutting straight lines 
on metal as they have been described and illustrated in this 








SLOTTING MACHINES 


57 


and the preceding chapter, we find the main characteristics 

to be rigidity, speed, and convenience. Comparing machines 

made in the United States now with those made twenty and 

«/ 

even ten years ago, there is evident a marked improvement 
in all th ree characteristics. The increase in strength and 
stiffness and in the area of bearing surfaces has made greater 
capacity and greater accuracy possible. The increasing use 
of air-hardening steels for cutting tools has brought about 
greater cutting speeds, although this is not so marked in 
planing machines as it is in lathes. 

But it is in adaptability, in capacity for a wide range of’ 
work, and in convenience of operation, that the modern 
machine leads all its predecessors. This is what increases the 
output of a machine more than mere strength or speed. 

‘ Slaughtering stock ' by taking deep and wide cuts is 
sometimes necessary, but as a rule it only evidences poor 
management. The normal function of a machine tool is not to 
remove the most metal possible in a given time, but to finish 
the work in the least time with the greatest accuracy and 
with the least waste of material. It is this feature of the 
machines just described which is most to their credit and 
which has so enormously increased the output per man and 
per machine in the last decade. 

The use of two or more cutting tools at a time, the auto¬ 
matic power feeds in all directions, and the arrangement of 
adjusting cranks and controlling levers within easy reach of 
the operator, have all helped in this development. 












CHAPTER III 

ENGINE LATHES 

36. Lathes in General. 

As lathes are used in the ordinary machine shop they may 
be classified as follows : (l) hand lathes or those used for 
hand finishing and polishing ; (2) engine lathes either with 
or without screw-cutting attachments; (3) turret lathes 

equipped with a turret in place of a carriage and tailstock ; 
(4) special lathes such as are used on only one class of work. 
As the so-called engine lathe is the most general in its capacity 
for doing all varieties of work and is the most used of any 
of those above mentioned, it will be first considered. 

The elements of which a lathe is constituted may be thus 
briefly indicated : ( a ) the bed ; ( b ) the headstock and its 
spindle ; ( 0 ) the carriage and its mechanism ; (cl) the tail or 
footstock for supporting one end of the work ; ( e) the gear¬ 
ing for changes of speed ; (f) the feed mechanism; (g) the 
mechanism for cutting threads. 

37. The Bed. 

The strains which come on the lathe bed are twofold : 
first, the bending due to the weight of the carriage and the 
pressure on the tool; and second, the twisting due to the 
pressure on the tool when turning large work and to the un¬ 
even support of the legs. As usually designed, the bed is 
well adapted to resist the bending but has very little capacity 
to withstand torsion. It consists of two parallel girders 

approximately of an I-section connected at intervals by cross- 

58 








20-INCH AMERICAN LATHE. 
































60 


MODERN AMERICAN MACHINE TOOLS 


I 


girts and supported on legs. This form in its various modifi¬ 
cations has come about rather as an adaptation of the frame 
to the moving parts than as an attempt to meet the con¬ 
ditions of strength and stiffness. The tops of the girders are 
convenient for attaching the fixed and moving parts, the 
recesses in the sides for locating the feed rods and lead 
screws, and the bottoms for fastening to the supports. The 
ideal cross-section, as far as strength is concerned, is the box 
form having its depth considerably greater than its breadth 
and the metal reinforced at top and bottom. In other words, 
complete the present form by covering the gap at top and 
bottom. Some enterprising builder will yet do this and 
make a bed having four times the stiffness for the same 
weight. The legs of the modern lathe are usually homely, 
and it would seem unnecessarily so. The use of reverse 
curves without apparent reason and the ungainly spreading 
of the leg in every direction give it an absurd appearance. 

As the beds increase in size and weight, cabinets or columns 
are substituted for the legs at one or both ends, as shown in 
Figs. 25 and 26. The combination of cabinet at one end and 
leg at the other is not pleasing and must be considered poor 
design. The convenience of cabinets as receptacles for gears, 
wrenches, and other adjuncts of the lathe is too apparent 
to need discussion. As the weight increases the cabinets 
naturally become more stocky, as in Figs. 27 and 28, and 
finally disappear altogether, the bed reaching to the floor and 
resting on stone, brick, or concrete foundations. (See Fig. 29.) 

I neven support by the legs is one serious cause of twist¬ 
ing in the beds of small and medium-sized lathes. This can 
be easily obviated by supporting the right end of the lathe 
on a hinge or rocker with its axis parallel to the lathe bed, 
thus allowing the leg to adjust itself for any lack of align-' 
ment in floor or foundations. 





The ways of American lathes are almost universally of the 
inverted V type, the angle between the sides of the V being 
about 90 degrees. The two outer ways are used for guiding 
the carriage and the inner ones for the tailstock. Flat ways 












Lodge and Shipley Machine Tool Co., Cincinnati, Ohio. 



































6 2 


MODERN AMERICAN MACHINE TOOLS 


have found little favour in the United States, one reason 
being the difficulty of keeping them clear of chips. On some 
lathes the inner ways are depressed as shown in Fig. 37, thus 
affording more room for bracing the carriage and giving more 
swing to the lathe. 

In others the inner V’s are omitted altogether, and the 
tailstock is guided on flat ways with bevelled edges. The 
omission of one V and reliance on the other for guidance 
is also a common modification. 

The principal change of late years in the ways of engine 
lathes has been towards an increase of bearing area and of 
the angle between the two sides of the V. 

As regards the general design of bed and legs, it may be 
said that there is of late a marked improvement in the way 
of simplicity, absence of ornament, and increase of strength. 
There still remains, however, the possibility of improvement 
by reverting to the closed box section, if the moving parts 
can be successfully adapted to this form. 

The use of pan frame for catching oil and chips has usually 
been confined to turret lathes, but several makers are supply¬ 
ing them when desired with their standard engine lathes. 
(See Fig. 32.) 

38. The Headstock. 

This is of practically the same pattern in all American ' 
lathes, as may be seen by reference to the various illustra¬ 
tions. It consists of a ribbed arch spanning the gap between 
the ways, sloped to match the shape of the cone pulley and 
having box-shaped standards at either end for the reception 
of the spindle boxes. In the best design the arch is con¬ 
tinuous, and is not cut away under the cone. Even the re¬ 
versing gear is sometimes moved outside to avoid weakening 
the headstock by cutting into it. In heavy turning on large 
work the principal strain on the headstock is a direct lift on 
the main spindle box; but in addition to this there is always 
more or less horizontal pressure tending to spring the box 
sideways. A comparison of the lathes shown in the illustra- 








ENGINE LATHES 


63 


n 

e 


tions with those 
increase in the len 


made ten years ago will show a decided 
gth and diameter of spindle bearings and in 



Fig. 27. 

24-INCH LATHE—ENI) VIEW. 

The R. K. Le Blond Tool Co., Cincinnati, Ohio. 


the width of steps on the cone. Eig. 30 shows the shape of 
the headstock and the general arrangement of the moving 









64 


MODERN AMERICAN MACHINE TOOLS 


parts in one such lathe. The only break in the continuity of 
the headstock is the one small opening for drainage. 

39. The Spindle. 

The main features of the head combination are the spindle 
and its boxes, the cone and back gears, and finally the feed¬ 
gearing connections. As is shown in Figs. 30 and 31 the 
spindle is usually hollow, allowing small rods to be finished 
in a chuck and then cut off. In fact the advantages of a 
hollow spindle are too apparent to need discussion. The one 
shown in Fig. 31 has an unusually large bore when the bush¬ 
ing and centre are removed. The journals are long and of 
large diameter, especially the one next the face plate. This 
latter journal may be considered one of the critical points in 
any lathe. Upon its accuracy and its stiffness depend the 
quality of all work done on the machine. Its length deter¬ 
mines the coolness of running at high speeds, its projected 
area must be sufficient to prevent squeezing out of the oil 
under heavy pressures, while its diameter must ensure 
strength and rigidity against torsion and bending. 

Crucible steel is the metal generally used, as this metal is 
strong and wears well. The bearings are usually ground, and 
the collars which take the end thrust are hardened and 
ground. The spindle boxes are made of phosphor bronze 
or other composition metal which can be readily cast, which 
presents a good rubbing surface when finished, and which will 
hold the oil. In many modern lathes lubrication is effected 
by ring oilers, as may be seen in Figs. 30 and 31. These 1 
illustrations also show two different types of box. That 
illustrated in Fig. 31 is the more common, a cylindrical bear¬ 
ing with the box parting in a horizontal plane through the 
centre. The cap is fastened by screws, and adjustment is 
effected by lining up or by planing. 

With bearings of the proportions shown and with con¬ 
tinuous oiling the wear should be very slight and adjustment 
seldom needed. 






\ 





E 


Schumacher and Boye, Cincinnati, Ohio. 













































6G 


MODERN AMERICAN MACHINE TOOLS 


The lathe illustrated in Fig. 32 has cylindrical journals on 
the spindle, but the boxes are conical on the outside and are 
adjusted by means of rings screwed on the ends forcing them 
in or out of conical seats in the headstock, thus keeping the 
spindle always in line. 

The lathe illustrated in Fig. 30, on the other hand, has 
conical bearings for its spindle, and adjustment is effected by 
endwise movement of spindle. 

The proportions of the cone and thrust collar at the front 
end are so adjusted that they shall wear together. The box 
at the rear has a separate adjustment. The arrangement just 
described permits of having a solid box and always keeps the 
alignment of the spindle perfect. 

The makers state that they have in their own shops bear¬ 
ings of this description which have been in constant use for 
two years without readjustment. 

A comparison of the spindle and cone dimensions for 
several of the lathes shown by the illustrations gives the 
following as average measurements : — 


TABLE IV 


Swing. 

Front Bearing. 

1 

Cone Steps. 

Inches. 

Diam. 

Length. 

Width. 

Diameter. 





Large. 

Small. 

14 

2'25 

4-25 

2-25 

9-0 

3 5 

16 

2-75 

4-875 

2-625 

10-5 

4-0 

18 

3-0 

5-0 

2-625 

12-5 

4-5 

20 

3-25 

5-5 

3-125 

13-0 

4-75 

24 

4-0 

7-0 

3-625 

15-5 

6-0 

30 

5-0 

8-0 

4-25 

20-0 

7-0 

36 

6-0 

9-0 

4-75 

220 

8-5 

42 

6-0 

10-0 

usually triple instead 

48 

1 

7-0 

12-0 

of double geared. 


Of course this table does not give a logical system of 
dimensions, but merely represents the average of the 
measurements for each size of lathe. 


























V■ 



54-INCH POND ENGINE LATHE. 

































68 


MODERN AMERICAN MACHINE TOOLS 


40. Speed Gearing. 

Lathes of the standard type are equipped with cone pulleys 
and back or double gearing to give the necessary changes in 
speed. The cone pulley and the small gear at the left (Fig. 30) 
forming one part and running loose on the spindle, transmits 
motion to the latter through the back gears and the large 
front gear on the spindle. When high speeds are desired, 



Fig. .30. 

IMPROVED HEADSTOCK OF ENGINE LATHE. 


The Hendey Machine Co. 


to the front gear by a screw or some other means. This time- 
honoured device is probably a survival of the fittest and will 
continue to be used indefinitely. 

The protection of the spindle gears by shields is a featurej 
that will be appreciated by most users of lathes. (See Fig. 25./ 
The matter of proper lubrication between cone and spindle 
deserves more attention than has apparently been given to. 
it. When the back gears are in use the cone is in the con-; 
dition of a loose pulley, and the tendency of the oil is to fly 
out away from the spindle. The usual method of oiling b> 
tubes from the outside of cone is a very poor solution and the 
sticking of the cone on the spindle an annoying accident. 

Another disagreeable feature of some lathes is the ten- 





































































































































ENGINE LATHES 


69 


dency of the back gears to fly out when in use. This is over¬ 
come to a greater or less extent in modern lathes by having 
the eccentric which controls the gears slip by the centre 
far enough to lock against the working pressure. One such 



Fig. 31. 

HEADSTOCK OF LATHE. 

Lodge and Shipley Machine Tool Co., Cincinnati, Ohio. 


lathe is equipped with friction gearing in the headstock, 
which can be changed while the spindle is in motion by 
means of a lever in front of the headstock. This arrange¬ 
ment is particularly convenient when finishing small parts 
requiring frequent changes of speed. llie time lost in chang¬ 
ing back gears in the ordinary way would be considerable in 
























































































































































70 


MODERN AMERICAN MACHINE TOOLS 

such case. The number of steps on the cone is either four or 
five, and the steps are generally of uniform height. This 
arrangement gives approximately a regular geometrical pro- j 
gression of speeds, and the back gearing is so graduated as to i 
preserve this ratio. That is to say, it ought to be ; candour ; 
compels the admission that it is not always so graduated. 

An examination of several of the lathes illustrated in this 
chapter shows a gearing ratio of about 10 to 1 as the average 
for 16-inch lathes, and a geometrical ratio of speed change 
from one step to the next of about 1*5. To illustrate this 
the following figures are quoted from one of the catalogues :— 

Swing over bed, 16f- inches. 

Ratio of back gearing, 9’25 to 1. 

Head-cone diameters, 3|, 5 T 7 ?7 , 7J, 8}§, 101 inches. 

Countershaft cone diameters, 121, 10}§, 9|, 7 T ‘ ¥ , 5f. 

Speed of countershaft, 100 revolutions per minute. 

The speeds of the lathe spindle will accordingly be as 
follows :— 

Without Gear. With Gear. 

333 199 128 84-5 54-75 35 2H5 13*8 9U5 5-92 

The successive values of the speed-change ratio from step 
to step are :— 

1-67 155 1-52 1*54 R52 H67 R55 1*52 R54 

The slowest speed, or 5*92 revolutions per minute, would 
give a cutting speed of about 25 feet per minute at the 
periphery of a circle 16 inches in diameter. 

Double back-gears are used where it is necessary to get a 
greater range of speeds without increasing the number of 
steps on the cone. The Draper lathe has two sets of gears at 
the back end of the spindle so arranged that either set may 
be thrown into mesh at will. With this arrangement it is 
usual to have less difference between the diameter of the 
successive steps than in the single-geared headstock. The 
lathe is more powerful with the belt on the small step than 
the ordinary lathe, and the belt is more readily shifted from 






The Bradford Machine Tool Co., Cincinnati, Ohio. 












72 


MODERN AMERICAN MACHINE TOOLS 

one step to another. The following figures give a reasonable 
arrangement for a double back-geared 24-inch lathe 

Ratio of first back-gearing, 4‘3 to 1. 

Ratio of second back-geari ng, 18 5 to 1. 

Head-cone diameters, 16, 13}, 11J, 9|. 

Speed of countershaft, 80 revolutions per minute. 


Assuming the cone on the countershaft to be the same as 
the head cone we have the following range of speeds 

Without Gear. First Gear. Second Gear. 

138 95-5 67 46 32 22 15-5 10*7 7-5 545 3*6 2-5 

The ratio is practically uniform and is 1*45. The slowest 
speed, or 2\ revolutions per minute, would give a cutting 
speed of about 16 feet per minute on a 24-inch circle. 

Lathes ofover 30-inches swing are usually triple-geared, as 
is illustrated in Fig. 29. A triple-geared headstock is one 
in which there are two back-gear spindles, the slower one 
usually gearing directly with the face plate or chuck. This 
arrangement is most clearly shown in Fig. 33. For con¬ 
venience and for greater driving power the gearing is usually 
placed on the front side of the head. This brings the pinion 
which drives the face plate nearly in line with the cutting 
tool. As will be seen from the illustration, the gearing is so 
arranged that the spindle may be driven directly by the cone, 
indirectly by the upper set of gears, or indirectly through 
both sets of gears and the face plate. As there are five steps 
on the cone, this device gives fifteen changes of speed. When 
handling heavy work on the face plate, the gearing direct 
to teeth on the latter near the cutting tool removes the 
tendency to springing and chattering. 

The arrangement of cone steps and gears on a 42-inch 
lathe is in one instance as follows :— 

Ratio of back gearing, 6} to 1. 

Ratio of triple gearing, 40§ to 1. 

Head-cone diameters, 10J, 13|, 16}, 19}, 22 inches. 

Countershaft ,, 22, 19}, 16}, 13|, 104 inches. 

Speed of countershaft, 100 revolutions per minute. 








ENGINE LATHES 


73 


1 he corresponding speeds of spindle will be as follows : 


Dir *ect. Double Gear. Triple Gear. 

210, 143, 100, 70, 47-7 33*6, 22-9, 16, 11% 7-6 5T7, 3-52, 2G6, D72, 1-17 


1 lie geometrical ratios from one speed to the next are as 
follows:— 


1 *47 D43 1’43 D47 l - 42 D47 143 T43 1*47 etc. etc., 

an average of 1*45 as in the previous example. Calculating 
the cutting as heretofore for the slowest speed of the lathe, 



Fig. 33. 

LATHE HEAD, WITH TRIPLE GEAR. 

The Bradford Machine Tool Co., Cincinnati, Ohio. 

we find it to be about 13 feet per minute at the circum¬ 
ference of a circle 42 inches in diameter. 

41. Feed Control. 

For feeding the carriages along the ways some lathes have 
a lead screw working in a split nut on the apron, some a 
splined screw driving gears in the apron which engage with 
a rack on the bed, and some a splined feed-rod entirely 
distinct from the lead screw. 

Although the lead screw is the universal means of driving 
the carriage for thread cutting, it is not well adapted for 

















74 


MODERN AMERICAN MACHINE TOOLS 


ordinary turning. Being a positive gear, it is inconvenient to 
throw in or out when starting and stopping a cut. Add to 
this the fact that the continual wear inseparable from its use 
for ordinary turning would soon ruin it lor screw cutting, and 
there are reasons enough for the adoption of a separate device 
for feeding the carriage. Cutting a spline on the lead screw 
that it may operate gears on the carriage is a compro¬ 
mise which has little to recommend it, as the spline forms 
cutting edges on the threads of the screw and these wear 
the nut rapidly. Large lathes which are to be used almost 
exclusively for ordinary turning may be made without a 
separate feed-rod, but for the small everyday lathe it is 
almost indispensable. 

An inspection of the illustrations in this chapter will show 
that nearly all the American lathes have the lead screw lor 
thread cutting and the combination of splined feed-rod and 
stationary rack for turning. The mechanism for actuating 
the feed-rod and lead screw is practically the same in most 
lathes, and consists of a train of gears driven by a pinion on 
the rear end of the spindle either inside or outside of head. 
The gear for reversing the direction of feed usually consists 
of two pinions on a swinging sector, either one of which may 
be brought in mesh with the spindle pinion by means of a 
convenient lever. This is the case with the lathes shown in 
Figs. 26 and 27. Fig. 27 gives an end view of a lathe geared 
on this principle, and shows the connection between spindle 
and lead screw so clearly as to need no explanation. In 
Fig. 30 the reversing mechanism is seen to be underneath 
the headstock and to consist of two bevel pinions revolving 
in opposite directions, either one of which may be engaged 
with a clutch on the shaft which drives the feed. 

This clutch is operated by a reversing rod running the 
whole length of the bed and manipulated at the carriage, and 
is also controlled by an automatic stop-rod worked by the 
carriage. 

This last-described method has the advantage of not 


ENGINE LATHES 


75 


) requiring the meshing of gears, and therefore can be readily 
i operated when the lathe is running*. 

o 

From the nature of its use the lead screw is necessarily 
driven by gearing without the use of belts or other friction 
devices. It is usually disconnected from the carriage or 
apron by a split nut (see Fig. 34) operated by a lever. 

[When driven by a reversing motion operated from the 



Fig. 34. 


STANDARD LATHE APRON. 

L The R. K. Le Blond Machine Tool Co., Cincinnati, Ohio. 


carriage, the lead screw may be reversed without reversing 
the spindle and the tool run back for another cut. 

This renders reversal of the countershaft unnecessary, and 
makes possible a two-speed counter with two open belts, 
thus doubling the number of lathe speeds. The number of 
different threads which can be cut depends on the size of 
lathe, but generally includes the ordinary pitches of bolt 
threads and pipe threads from 1 or 2 to 32 threads per inch. 
The lead screw is sometimes located just inside the bed. 

The feeding mechanism for plain turning may be driven by 
belts, by gears, or by the two combined. Fig. 27 shows the 
very simple method of driving the feed-rod direct from the 
spindle by means of a belt running on cone pulleys. For the 
















76 MODERN AMERICAN MACHINE TOOLS 

ordinary run of work, the simplicity and directness of this ! 
form of drive appeals to most operators. The absence of 
gears and of intermediate shafts with their accompanying 
noise and dry bearings is a welcome feature, lhe length of 
the feed belt will make it drive better and last longer. On 
large lathes a silent chain replaces the belt. The direct feed 
can be replaced by a geared feed whenever desired, and all 
feeds can he reversed at the carriage. 

The idea of obtaining changes of feed either for turning or 
cutting threads without changing gears now finds consider¬ 
able favour among lathe manufacturers. A series of gears is 
arranged in a ‘ nest ’ or group so that by merely manipulating 
a lever any one of the series may be brought into action. By 
having two sets of changes quite a number of combinations 
may be made. Figs. 25, 26, 28, and 31 show various modifi¬ 
cations of this plan. 

The Springfield lathe has a circular disc at the end of the 
head carrying eight gears arranged in a circle so that any one 
may he brought into line with the lead screw at will. The 
intermediate gears between head spindle and lead screw are 
arranged in pairs, such as to give five different ratios. The 
combination of these with the eight gears before mentioned 
gives forty different speeds to the lead screw. The range 
of threads is from 2 to 56 per inch, and the feed, being 
geared to the screw as 1 to 4, ranges from 8 to 224 cuts per 
inch. 

The more usual arrangement is that shown in Fig. 31, 
where a nest of gears is contained in the bed under the head- 
stock. By means of a lever in front of the head (see Fig. 26) 
a gear driven by the spindle may be thrown into mesh with 
any one of these. A series of four gears on the outside end 
of the cone-gear shaft multiplies the number of changes four¬ 
fold. Thus with nine gears in the cone, as shown in the cut, 
there would be 36 different speeds for the lead screw. The 
lathe shown in Fig. 26 has a range of 37 different threads 
from 2 to 32 per inch, any one of which may be cut without 




ENGINE LATHES 77 

changing any gears by simply shifting the two knobs shown 

in the figure. 

© 

The lathe whose headstock is shown in Eig. 30 has a some¬ 
what similar arrangement of gears. All the regular threads 
from 6 to 20 are cut by the simple change of a lever, and by 
two further changes of intermediate gears all the regular 
threads from 1 ^ to 80 per inch may be cut. 

For ordinary changes of feed the lever alone will suffice, 
the ratio of feed to lead screw being 1 to 5 on an 18-inch 
lathe. 

The 30-inch lathe illustrated in Fig. 28 has 32 changes 
for feeding and screw cutting without removing any gears. 
These changes are effected by combinations of two groups of 
gears, one containing four gears and the other eight. The 
following index is a good illustration of those used for screw 
cutting on this class of machines, being that for a 24-inch 
lathe of the same make. 


INDEX 


Front Index Handle 

in Hole, 

. 1 

2 

3 4 

r> 

6 

7 8 

Top Index Handle in 

Hole, 1 Cuts Threads per inch, 1 

If 

n 1-1 

i 7 1 i 

1 1 6 1 2 

G 1! 

11 11 

„ 2 

2 

99 w 

21 

91 93 

2 r 

3 

34 34 

11 n 

11 d ,, 


4l 

5 54 

5 1 

6 

64 7 

99 99 

4 

99 99 

„ 8 

9 

10 11 

114 

12 

13 14 

FEEDS 5 TIMES THREADS PER INCH. 

„ 16 18 
W. T. Emilies Patent, 

20 22 

Aug. 26, 1 

23 

902; 

24 

Oct. 

26 28 
28, 1902. 


It will be noticed that the feed ratio on this lathe is as 1 


to 5. 


Lathes having both the lock-nut screw feed and the rod 
feed should be so constructed that it is impossible to throw 
both into gear at once, as this latter combination is a most 
fruitful source of broken gears and racks. In some lathes it 
is possible to throw out the pinion from contact with the rack 


when cutting threads. 

Summing up, it may be said that the most noticeable im¬ 
provement in feed mechanism of late years is the substitution 
















78 


MODERN AMERICAN MACHINE TOOLS 


of combination gears for the ordinary change gears, making 
it possible to secure almost any cut or thread by the mere 
shifting of a lever. The convenience of this operation as 
compared with the old method ensures a more frequent 
use of the best feed and a consequent increase of output. 
There has lately been a more careful study of the subject 
of cutting speeds and feeds, and, as has been shown, an 
adaptation of the lathe gearing to meet the requirements of 
the operator. 

Another improvement is the location of the feed reverse 
in the apron of the carriage, a notable time-saver. 

The automatic stop on most lathes makes it safe to leave 
the lathe running when turning long work or when doing a 
large number of duplicate pieces. 


42. The Carriage. 

There is practically but one type of lathe carriage in use 
on American lathes. It is of H-form in plan, with a long 
slide on the front way, another sliding on the rear way, and a 
bridge spanning the gap in the bed. The tool slide traverses 
the bridge from front to rear, and the whole carriage is moved 
by gearing attached to the apron which hangs down in front 
of the bed. 

Although this general type is adhered to there is an 
almost infinite variety of detail. Fig. 35 gives a good idea of 
the proportions and arrangement of the ordinary carriage for 
a medium-sized lathe. As may be seen from the illustration, 
the V’s are at the extreme front and rear of the bed, while 
the bridge is cut away to clear the head- and tail-stock ways. 
This weakens the bridge, and has led some makers to adopt 
the sunken V. The bridge is, however, reinforced at the 
centre by braces to resist the thrust of the tool-post when that 
member is located as shown in the figure. To prevent lifting 
or springing of the slides they are gibbed to projecting ledges 
on the bed as may be seen from the cut. 








ENGINE LATHES 


79 


Some lathes of small size have a slide for the tool-post 
i which is hinged to the front of the carriage and raised or 
lowered by a screw at the back. In the majority of cases, 
I however, a compound rest is used which moves on a dove- 
!tailed slide and is controlled by the cross-feed screw, the 
elevation of the tool being effected in the tool-post itself. 
i T-slots should be milled in the top surfaces of the carriage for 
ithe attachment of work or of compound rests. (See Fig. 32.) 
Most lathes are fitted with both compound rests and simple 
block rests. The rest and tool-holder shown in Fk 29 is a 



Fig. 35. 

CARRIAGE OF BRADFORD LATHE. 

good example of what may be expected in large lathes, while 
most of the other dlustrations show the common tool-post 
with concave ring and elevating wedge. Power cross feed is 
now the rule where it was once the exception, the screw 
. being driven by a pinion as may be seen in Fig. 35. In most 
lathes both lateral and cross feeds can be used at once. One 
convenience that will be appreciated by all operators is the 
, Graduation of collars on cross-feed and compound-rest screws, 
thus furnishing micrometers for the adjustment of the 

tool. 

The general style of rests used on American lathes can 
be seen from the illustrations and requires no special 

description. 
















80 


MODERN AMERICAN MACHINE TOOLS 


43. The Apron. 

T1 iis is the term used by American builders to designate 
the plate in front of the carriage which contains the actuating 
mechanism for lateral and cross feeds. Two styles only will 
be illustrated, and these maybe regarded as typical. Fig. 36 | 
shows the interior of an apron where both feeds are actuated 



Fig. 36, 

INSIDE OF APRON. 

The Hendey Machine Co., Torrington, Conn. 

by worms sliding on a splined lead screw. For cutting threads 
the split nut at the extreme left is closed on the screw as 
shown. The worm at the right through a train of gears 
drives the rack pinion for the lateral feed, while the one at 
the centre drives the cross feed in a similar manner. The 
mechanism is too apparent to need much description. The 
rod at the lower part of the figure has no connection with the 
apron mechanism, but is used for reversing the feed gears in 
the head, as explained in a previous paragraph. 

The apron illustrated in Fig. 34 has separate drives for 
feeding and screw cutting. The lead screw only operates 















ENGINE LATHES 


81 


when the nut at the extreme left is locked, while the feed 
mechanism is driven by a splined rod running through the 
bevel pinions shown near the centre. 

These pinions and the bevel gear constitute the reversing 
motion for the feeds and operate both cross and lateral feeds. 
The rack pinion can be disengaged from the rack when screws 
are being cut, and suitable locks make it impossible to engage 
both screw and rod at one time. 

On large lathes it is customary to have two bearings to 
support the rack pinion, one on either side the rack, and for 
additional rigidity to have the lower edge of the apron bear 
against a parallel ledge of the bed. Lathes larger than 20- 
inch of the kind shown in Fig. 26 have these improvements. 

All lathes of the ordinary sizes are fitted with an attach¬ 
ment at the rear of the carriage for turning tapers, as it is 
pretty well understood that setting over the tailstock is an 
awkward and unwork manlike method of accomplishing this 
result. Fig. 35 shows the taper attachment in section. In 
brief, it may be said that the attachment when in use moves 
the cross-feed screw endwise without turning it, thereby 
moving the tool rest. This motion does not interfere in the 
least with the ordinary use of the cross feed, since the crank 
shaft telescopes in the screw and drives the latter by a key 
or spline. 

In the best modern lathes the carriage is equipped with 
the following control levers or wheels all within easy reach of 
the operator : hand feeds, lateral and cross; power feeds in 
both directions ; feed for screw cutting automatically locked 
out when other feeds are in use ; reverse lever for all or part 
of the feeds; automatic stop for straight turning. 


44. The Tail- or Foot-Stock. 

There is but one form of tailstock in general use on 
American lathes as shown in most of the illustrations. 


F 







82 


MODERN AMERICAN MACHINE TOOLS 


The ‘curved’ tailstock, as it is usually called, is so cut 
away in front as to allow of the carriage being run back ; 
against it when the compound rest is set at 90 degrees. It 
is in two parts, the upper part being adjustable on the lower 
to offset the tail spindle when desired. The ways for the 
tailstock may be made in a variety of shapes ; the front one 
may be flat, or the V s may be omitted altogether and the tail- 
stock be guided by bevelled edges inside the bed. This latter 
arrangement leaves more room for the carriage, permitting a 
deep and stifle r bridge. The clamping bolt, if but one is used, 1 
should be near the front end of the base. In addition to this, 
a brace or latch underneath may be arranged to engage a rack 
in the bed and help hold the stock against the thrust of the 
work. 

Lathes such as shown in Fig. 26 have this last-mentioned 
device. 

For moving heavy tailstocks on the ways a pinion engaging 
with the feed rack is turned by a crank in front as illustrated 
in Figs. 28 and 29. These figures show the use of two clamp¬ 
ing bolts, which is to be recommended for large lathes. The set- 
over adjustment is sometimes located above the holding-down 
bolts and independent of them. This combination permits 
setting over without loosening the base, when heavy work 
is on the centres. 

The tail spindle is actuated by a screw which should have a 
thread bearing inside the spindle all of the length of the latter 
except that occupied by the centre. Morse tapers Nos. 4 to I 
6 are in general use for the centres on both head and tail 
spindles. It is the general practice to have the spindle 
clamped near the front end by a split hub and binding screw. 
This shows in most of the illustrations. 

I he size of the tail spindle is a matter of nearly as much 
importance as that of the head spindle, since it is impossible 
to do work of the full capacity of the lathe unless the supports 
of the work are rigid and well aligned. 

An examination of three makes of lathe such as have 






ENGINE LATHES 


83 


already been referred to in this chapter discloses the following 
average sizes of tail or dead spindle :— 

Swing in inches, . . 14 1G 18 20 24 30 36 42 

Diameter of tail spindle, . If If 2 2J 2| 3J 4 4f 

45. General Considerations. 

A comparison of the lathes illustrated in this chapter with 
those made in this country twenty or even ten years ago will 
show improvement along several different lines. 

The lathes are heavier and more massive than formerly for 
the same rated capacity, and the strength and stiffness of the 
moving parts has increased in proportion. It used to be said 
with some show of reason that an 18-inch lathe was simply 
a 16-inch machine blocked up. This criticism no longer holds, 
and it may safely be said that an 18-inch lathe will turn work 
up to its full range of swing without trembling or chattering ; 
and so of the other sizes. 

It is, however, in adaptability and convenience of operation 
that the American lathe is pre-eminent. The combination 
of gearing for feeds and speeds easily and quickly changed 
and the reverse motion within easy control of the operator, 
make it possible to turn out large amounts of product and 
thereby save in all operating expenses. 

The shipping weights of the various sizes of lathes are 
averaged as follows :— 


Swing, . 

14" 

16" 

18" 20" 

24" 

30" 

36" 

42" 

Bed, 

6' 

8' 

10' 10' 

12' 

12' 

12' 

12' 

Weight in lbs. 

O 

1500 

2000 

2800 3500 

5000 

8000 

11,000 

18,000 


46. Cutting Speeds. 

The speeds formerly recommended were from 20 to 30 feet 
per minute for wrought iron and soft steel, and somewhat 
more than this for cast iron. The latter metal has been 
successfullv turned with ordinary carbon steels at a speed of 
40 feet per minute. 











84 MODERN AMERICAN MACHINE TOOLS 




The use of the new high-speed steels has made a great 
change in these figures as far as they apply to soft steel, from 
80 to 160 feet per minute being not unusual in turning this 
metal. In turning cast iron the change has not been so great, 
speeds of from 50 to 75 feet per minute being as high as can 
be recommended for this material. 

Many experiments have been made with the different 
varieties of air-hardeninof steels to determine the best steel, 
the best speed, and the maximum endurance. One of the 
most complete sets of such tests was made by the Lodge and 
Shipley Machine Tool Co. of Cincinnati, Ohio, and reported 
in the American Machinist for January 7, 1904. Seven J 
different brands of high-speed steels were tested for endur¬ 
ance and speed, and the two best were then given further 
tests as to endurance and capacity for removing metal. 
Table 5 gives a few of the results obtained with the best of 
the steels tried. 

TABLE V 


Material Cut. 

Number 
of Cuts 
made. 

Cutting 
Speed in 
Feet per 
Minute. 

Depth of 
Cut in 
Inches. 

Length of 
each Cut 
in Inches. 

Time of 
each Cut 
in 

Minutes. 

Machinery Steel, 

1 

201 

1 

8 

14f 

1 49 

Cast Iron, . 

1 

106 

a 

8 

9 

2.46 

55 55 

1 

94 

1 

o 

9 

2.46 

Machinery Steel, 

9 

169 


19 

1.40 

55 55 

11 

155 

i t0 I 

3 

1.0 

Inn* 

16 

167 

3 

8 

if 

2.10 1 

1 55 51 

16 

167 

7 

3 2 

14 

3.58 / 


In each instance the tool made the number of cuts recorded 
without re-grinding and was in good condition at the end of 
the test. The two runs bracketed together at the last were 
made by two tools jointly. 

Some very interesting experiments along these lines were 
made in Manchester, England, under the direction of the 



































HIGH-SPEED LATHE. 



















86 


MODERN AMERICAN MACHINE TOOLS 


Manchester Association of Engineers, and reported by I)r. 
J. T. Nicholson, Professor of Engineering in the School of 
Technology of that city. It would be impossible to give here 
even an abstract of these very complete experiments, but it 
would repay those interested in this subject to obtain a copy 
of the report. Dr. Nicholson finds the maximum allowable 
speed to depend upon the area of cut and the nature of the 
material machined, and gives the following formulas as repre¬ 
senting approximately the relations. 

Let v = cutting speed in feet per minute and a = area of 
cut in square inches, i.e. product of depth of cut by feed, then— 

For soft steel, . . . ~ rawr r + ^ 

a+0*011 


For medium steel, 
For hard steel, 


1*823 

a + 0-016 + J 

1 *77 . K 

-——— 4- D 

a + 0-027 


For soft cast iron, . 
For medium cast iron, 
For hard cast iron, . 


v= 115 — 13a 
v= 63 —858a 
v= 40 —400a 


Dr. Nicholson further found that a speed of 90 feet per 
minute could be maintained on soft steel, and that the new 
steels would cut about four times as fast as the ordinary 
steels. He found no tool which would run two hours at T a 
speed of 34 feet per minute on medium cast iron. On the 
whole, the speeds given in this report are considerably less 
than those reported from the Cincinnati tests. 

Some actual examples of work in railroad shops are given 
in the American Machinist of March 5, 1903. In one case 
two tools removed 62'5 cubic inches of metal per minute from 
a 9-inch forged steel shaft at a cutting rate of 125 feet per 
minute. This would be at the rate of over 1000 lbs. per hour. 

Another rapid-reduction lathe made by the Lodge-Shipley 
Co. with three cutting tools removed 113 cubic inches per 
minute from 50 carbon steel or at the rate of nearly 1900 lbs. 
per hour. The cutting speed in this instance was 50 ft. per 
minute. 






ENGINE LATHES 


87 


A study of the results obtained with the new steels in 
everyday service leads to the following conclusions : that in 
turning soft and medium steels, cutting speeds of from 80 to 
120 feet per minute are easily maintained; while for finishing, 
speeds of from 160 to 200 feet per minute are not uncommon. 


That cast iron is a more difficult metal to treat, the limit 
being from 50 to 75 feet per minute for roughing and some¬ 
what more for finishing. The use of the high-speed steels 
and the resulting increase in the amount of metal removed 
per hour necessitates a change in the design of the machine 
itself. It must not only be strong and rigid in all its parts, 
especially so in the spindles and the carriage, but it must also 
have greater driving power. 

Fig. 37 illustrates a lathe designed for this class of work. 
It possesses the usual conveniences for rapid work such as 
have been enumerated in this chapter, and is furnished with 
spindles and carriages of extra strength. 

Its principal peculiarity, as may be seen from the cut, is 
the large belt contact on the cone pulley. The steps are only 
three in number, and are wide enough to accommodate a 
4-inch double belt. The back-gear ratio is only 2* 13 to 1, and 
a two-speed countershaft is employed, giving twelve changes 
in all. The highest speed is only four times the lowest, and 
all are so graduated as to give a cutting speed of approxi¬ 
mately 160 feet per minute on work from one inch to four 
inches in diameter. 

The important fact to be noticed in this connection is that 
belt power is what determines the cutting power, and that no 
ratio of (rearing will enable the machine to do its work if the 

O O 

belt is not large enough. 


47. Horse-Power of Lathes. 

It is frequently desirable to know the probable power 
required by machine tools when planning a shop or factory, 
especially if electricity is to be used as a motive power. 







88 


MODERN AMERICAN MACHINE TOOLS 


The General Electric Co. published in the American 
Machinist for April 30, 1903, a list of sizes of electric motors 
as installed by them for driving machine tools. In this list 
are given the following sizes for engine lathes :— 


>5 


Speed lathes,. 

22" and 24" lathes, 
26" and 30" 

36" and 42" 

48" and 54" 

60" lathes, 


55 


'9" 


55 


84" 




H.P. 

1 

2 

H 

H 

5 “ 

6 


71 


10 




These sizes are given as the result of tests made on machines 
in everyday service, but would not apply to lathes where 
high-speed steel is employed on roughing work. 

Experiments made by the writer on small lathes with 
ordinary tools have shown an average of about one-half a 
horse-power consumed by lathe and cut when removing from 
10 to 20 lbs. of cast iron per hour, the lathes being from 16 
to 22 inches swing. 

Reports of tests by Professor John J. Flather give about 
the same results. 

Some tests conducted at the Baldwin Locomotive Works 
on electrically-driven lathes showed the following power 
consumption :— 






Horse-Power : 

Kind. 

Size. 

Material Cut. 

Number 

Tools. 

Total 

when Cutting. 




Min. 

Max. 

Avge. 

Wheel Lathe, 

84 in. 

Cast iron 

9 

•J 

2-9 

7-9 

6-1 

55 55 

84 in. 

>> ?? 

9 

4-2 

5-8 

5-1 

5) 5) 

84 in. 

55 55 

2 

5-3 

6-2 

5-8 

>5 55 

90 in. 

,, steel 

9 

-j 



6-38 





































ENGINE LATHES 


89 


The issue of Machinery (New York) for March 1903 
contains quite complete reports with regard to the horse¬ 
power of the machine tools in two American railway 
shops. 

In the new shops of the Union Pacific R.R. at Omaha, 
Nebraska, electric motors are used on all the tools, and the 
following powers have been selected for engine lathes :— 


Size of Lathes. 

16 in. x 6 ft. . 

18 in. X 8 ft. . 

20 in. x 10 ft. . 

22 in. x 12 ft. . 

24 in. X 12 ft. . 

26 in. x 12 ft. . 

30 in. x 14 ft.. 

36 in. x 16 ft. . 

42 in. x 16 ft. . 

80 in. driving wheel lathe, 


H.P. of Motor. 

1 to 2 
2 

91 

• 2 
2 

H 

91 

• ^ 2 
24 

3 

3 

71 

1 2 

15 


Tests of machine tools in the locomotive shops of 
the Buffalo, Rochester and Pittsburgh R.R. showed the 
actual power absorbed by various engine lathes to be as 
follows :— 


Kind of 
Lathe. 

Size of 
Lathe. 

Number 
of Tools. 

Horse-Power. 

~T~ 

Starting. Cutting. 

Wheel 

42 in. 

one 

4-6 

0-5 


79 in. 

two 

. . . 

4-0 

Engine 

28 in. 

one 

4-7 

2-5 


The wide difference between the power required for 
starting and for steady running will be noticed. This points 
to one advantage of the group system in driving machine 





















90 


MODERN AMERICAN MACHINE TOOLS 


tools, since it will not often be the case that all the maciuj 
will start at once and a smaller motor can be used. 

Experiments made by the writer on lathes of from 14 to 22 
inches swing, using one tool of ordinary steel, gave the 
following as the horse-power for cutting metal : where w = 
weight of metal removed per hour :—- 


H.P. = - 035 w for cast iron. 

H.P. = *067 w for machinery steel. 

To this must be added the horse-power required to run the 
machine itself, which should be not over 0*1 h.p. for the 
machines mentioned. 

Experiments made with the air-hardening steels and high 
speeds naturally show a great increase in the power re¬ 
quired. 

The tests made by the Lodge-Shipley Company which have 
already been alluded to showed the limits to which this can 
be carried. One of the Company’s special high-speed lathes 
of 20-inches swing, using self-hardening steel and cutting at 
the rate of from 121 to 175 ft. per minute, consumed from 
7*1 to 15*9 horse-power on different cuts. This included the 
power required to run the counter and the lathe itself. The 
material cut was machinery steel, the depth of cut r ] F inch, 
and the feed from ^ to ^ inch. With deep cuts a greater 
horse-power even was recorded, in one instance reaching* 
30 h.p. 

The following table presents a summary of some tests 
on large lathes made under the direction of the writer and 
reported in Ccissiers Magazine for December 1903 : 



ENGINE LATHES 


91 


>22 = 

tlieT 

-r - csj 

W 

a 

H 
P 
O 
J1 


the 

tlie 

# 

re^ 

ave 

m 

iies 

at 

'>in 

tlie 

lie 

li 

rer 

>te 

id 


5 

o 

l-H 

X 

o 1 


Q 

55 

W 

O 

t-h 

hH 

gq 

w 


s 

H 

Em 

o 

EM 

o 

hH 

HH 

W 

hH 

HH 

H 

5? 

HH 

C/2 

§3 

H 

H 

fb 

O 

Ph 


h-> 

1/2 


H 

PP 

< 

EH 


05 

55 

P<5 

w 


PM 

I 

w 

75 

pH 

o 

tc 


3 

> 

o 

HH 

s 

s 

ov* 


<! 

H 

W 

k—I 

A 


w 


w 

75 

o 

K 


• ?H 















r-H rH 




Per Llo 
er Hon 

Cl ^ 








OP 

OP 

CO 

IP 

-+l 

1 - o 

O i—i 

GO 1—H 

t—H 

CO 

CO -rf 








CT) 

CO' 

>o 

CO 

CO Cl 

ip r-H 

OP Cl 

-M op 

OP 

CO 

o o 








o 

O 

o 

o 

o o 

O O 

r-H t—H 

o o 

O 

o 

6 o 








o 

o o 

o 

o o 

o o 

o o 

o o 

o 

b 

Ph 



















r-H 



















hH 

o OP 











IP 

lO r-H 

O i—i 


OP 


co 

rJ ^-1 

OP GO 








r-H 

t—H 

o 


co 

05 IP 

IP 'GO 

IP 


CO 


-r+H O 








T—H 

OP 

05 

ip 

-H CO 

C/D T—l 

-M CO 

i- 05 

05 

ip 

• • 

• • 


• 

• 

• 

• 

• 

• 

• 

• 

• 

• • 

• • 

• • 

• • 

• 

• 

Jh qt 

o o 








t-H 

o 

o 

o 

O O 

o o 

Cl t—h 

o o 

o 

o 

,2 Ph 



















H 



















C2 r/j 






CO 

05 

o 







t—h 

t—H Cl 

Cl 

OP 

O r^- 

OP rp 1 

OP -rH 

CO 

CO 


CO 

OQ 

l— 

OP 

o 

io 

OP 

Cl o 

O 

CO -H 

ip CO 

t— 

o 

W g 

O CO 

ib ci 

r —A 


CO 

CO 

Cl 

io 

CO 

05 

IP 

CO 

Cl 1- 

co co 

r-H r-H 

-b o 

Cl 

OP 

s-j o 

■HH OP 

^H ^ 

io 






io 

o 

Cl 

t—H 

CO CO 

r—H CO 


t—H 

t—H 


rgfS 










r-H 









pH 
























io 














-- ^ 

co 

co o 


05 

05 

o 

o 

co 




co 

ip IP 

ip CO 

CO T—l 

t- 

CO 

o 

| ^ A 

io co 

l - CO 

05 

1^ 

1 — 

co 

OP 

Cl 

o 

i- 

o 

05 

l'- IP 

O CO 

-~+i ip 

CO CO 

CO 

CO 

I r C d 

-H O 

co io 

O cb 

CO 

o 

o 

o 

o 

CO 

OP 

cb 

OP 


CO CO 

t—H t—H 

o o 

t—H r-H 

r-H 

b 

Pm 



Cl 






Cl 

r-H 

OP 
















r-H 

Cl 




















OP 

>o 








C5 CO 








—M 

Cl 

OP 


t—h gO 

-tH o i 

r-H l> 

Cl CO 


co 


Cl 1- 








lO 

05 

CO 


O CO 

O co 

Ol T— < 

Cl OP 

i- 

ci 

t-H Cl 








CO 

co 

t—h 

o 

r-H O 

1-H O 

o o 

o o 

b 

b 


ci 

43 

O 


t- <05 

ip o 
ci Ph 


(MlC^aiiO^O5iO00(MCCl> 

Ol0MQ0C0C0®C0WO05»0 
.. 

Cl GO t-Hi <0 r—H t—I r-H lO IP CO <0 


IP GO H 
O GO b 


o >P 1' 

r- i- 


1 — 1 L— 
CO L~- 


^H t-H t-H (3> O) C^> t-H t-H C^> 


5 

S-i 43 

0) 2 

H o 


+3 S 

5 Pi 


05 

05 

43 

X 


op O 
ci ib ci 


' 4-3 

75 

/«H 

6 


05 

rs rv 

CN ) -> #N 

m 


4-3 

75 

c3 

o 


lO 

GO 1- lO 

• • cb 

CO 


O O IP iP lO 

rH Tl> p Cl b 

i—H r-H r— h t—H CO 


lO (N 

iO o O O t— lO'-fOOOOiOO 

OiOCUHiOtOMClClbcOOCO 
Cl lO Cl Cl Cl Cl 


05 


o 


05 O 


S 3 
S 

05 „ 

P-i 05 . 
c3 i— 1 
05 X 
biD c5 

i- 

Oh 05 


Sh 

453 


05 

Oh 


75 > 

bio £ 


b •= o 

T-H lO 

GO b 00 

1—1 43 43 

X - 73 

05 „ 


05 * 

(—• 

44 
• r-H 

b >0 

r-< 

hh 

05 

'"C 

05 

fn 

ct 

05 

bD - 

< pH 

05 o 

.b o 
b S 

« b 
tM -d 

oo q, 
X ~ 

. 05 


pT ‘0 

o >— 1 

1 o 

^ O 


05 

o ^ 

Cl 43 
~ C$ 
05 — 1 

hC r-H 

443 05 
<3 05 


05 55 

bp ^ 

Co • 
^ > 
0 > 
a> b- 

H 

»»H 

bCjb 

S o 


05 

o 


> 

05 


05 


43 

o 2 


43 

C3 


43 

c3 


Cl 


Cl 


05 7 " 

2 SCO 

rr = o 
^ r oo 

I ^ _ 

HH * I ^ 

o3 dP c3 

05 


Cl "rf 
—H CO 


o3 * 
05 PP 
bO^P 
05 

"Ph^P 
’C tc- 

43 

P- 
. O 
P 43 
• tH O 

TO 2 

CO 


ihT ^3 
05 (T) 

PP Ph 

43 ^ 

-H • 

Ph ® 

lO 

P i '- 

O CO 

• r-H 

<n 

g -4-P 
05 C« 

43 

X! r 

05 pL, 

P ^ 

• r-H 

co ‘P 
H t'- 

® o 

• 43 

p o 

,rH a 

GO 

Cl 























































92 


MODERN AMERICAN MACHINE TOOLS 


The machines in this case were doing the ordinary work of 
the shop, and no attempt was made to crowd them. Self- 1 
hardening steel was used for all the tools, and the machines 
were driven by independent motors. For further parti¬ 
culars the reader is referred to the journal mentioned. 


48. Electric Drives. 

The problem of driving by electric motors is simpler in the, ! 
case of lathes than in that of reciprocating machines like 
planers and shapers, since electricity is best adapted to pro¬ 
ducing continuous rotary motion. 

For small lathes the group system of driving has several 
advantages. This method usually involves the use of a short 
line shaft driven by a motor and sufficient for perhaps five to 
ten machines each having its separate countershaft. If the 
lathes are of the same size and have a reversing mechanism 
independent of the countershaft, one long counter may be 
used for the group with friction clutches over each machine, 
thus doing away with the line shaft and its friction. The 
group system permits the use of constant-speed motors of a 
larger size, and at the same time divides the large starting 
torque so as not to be felt so much by the motor. 

Where there are no large machines and the group 
system is used exclusively, two-phase or three-phase alter¬ 
nating current can be employed at some saving of time and 
repairs. 

Machines requiring more than two or three horse-power 
can be equipped with separate motors to advantage, thus 
securing a certain amount of flexibility as regards arrange¬ 
ment and electrical speed-control. In such case direct- 
current motors are to be used, and by the combination of con¬ 
troller variation and mechanical means a large number of 
speeds may be easily secured. 

As has been noted in the case of planers, several different 
methods of mounting and connecting the motors have been 











24-INCH LATHE, ELECTRICALLY DRIVEN. 

















94 


MODERN AMERICAN MACHINE TOOLS 


employed. One lathe has a motor bolted to the rear ol the head 
cabinet and connected by a belt to a countershaft swinging 
on arms just above. This arrangement is compact and allows 
of the use of a constant-speed motor, but the cone belt con¬ 
nections would seem to be rather short for the best efficiency. 
The sizes of motor recommended, run by even gradations 
from 2 horse-power for an 18-inch lathe to G horse-power for 
a 36-inch lathe. (Compare with recommendations of the 
General Electric Co. in the preceding section.) 

Connection of the motor by gearing is the more common 
arrangement as being most economical of room. The motor 
is usually mounted above the headstock and gears to a quill 
on the spindle; by means of a variable-speed motor with con¬ 
troller and the usual back gearing a wide range of speeds can 
be obtained. The controller is located on the carriage, 
putting the speed-control within easy reach of the work¬ 
man. 

Fig. 38 shows an ingenious application of a constant-speed 
motor to a lathe, the changes of speed being effected entirely 
by gearing. As may be seen, the motor is hung underneath 
the bed of the lathe and connects with the spindle by a 
train of gears. The regulation of speed is effected by means 
ol the levers shown projecting from the headstock, while 
the reversing motion is underneath and controlled directly 
from the carriage. 

Comparing this method with that just described, where a 
variable-speed motor is employed, the greater complication 
of the mechanical control is evident. 

Electrically the constant-speed motor is simpler and more 
efficient, but all things being considered, it would seem as if 
electrical control was more convenient for the operator and 
represented a more advanced stage of development in the 
application of electricity. 

h ig. 39 shows the application of a variable-speed motor 
driven by the multiple voltage system, to the 27-inch lathe. 
As a motor of this type must furnish the power required to run 





































96 


MODERN AMERICAN MACHINE TOOLS 


the machine at its lowest speed, a much larger motor is neces¬ 
sary than when a constant high speed is employed. For in¬ 
stance, in the case of the machine just mentioned the powers of 
the motors at normal speed and high voltage would range from 
3j horse-power for an 18-inch lathe to 18 horse-power for a 
36-inch lathe, being from two to three times the sizes 
required under the other system. 












CHAPTER IV 

SPECIAL LATHES, INCLUDING TURRET LATHES 

49. Gap and Extension Lathes. 

The same general remarks made in Chapter I. with regard 
to widened planers are applicable to gap lathes. Increasing 
the swing of the lathe without strengthening the parts to 
correspond, and with the intent to deceive the customer, is 
bad engineering and bad business. 

Some manufacturers of cheap machinery in the past have 
tried to do this, and to foist upon their customers 18-inch 
lathes which had been ‘ raised ; from 16-inch, on much the 
same principle that unscrupulous rogues raise bank notes 
from ones to tens. Such deceivers can never prosper in the 
long-run, and sooner or later lose reputation and trade. 

To-day the tendency is to cut down rather than to raise, 
and the 'heavy’ 16-inch lathe has the strength and weight 
of the former 18 or 20 inch. The gap or extension lathe is 
not an attempt to deceive any one ; it is avowedly a com¬ 
promise and stands for what it is. 

The large manufacturers, having a great variety of machines, 
may have no use for such. A lathe which tries to turn 
18-inch work and 36-inch work will probably not be quite as 
efficient for either as if it had been designed for one alone. 
But the small or medium shop, especially the job-shop, is 
usually in need of just such machines. A limited number of 
tools with the widest possible range is the requirement. 

Fig. 40 illustrates the usual arrangement in machines of 

G 





•28-INCH * 18-INCH EXTENSION LATHE 























SPECIAL LATHES 


99 


this kind, the gap being obtained by sliding back the top half 
of the bed on longitudinal ways when large work is to be 
swung. The gap can thus be made wide or narrow as occa¬ 
sion demands, and the extension bed is then firmly bolted to 
the bottom bed. 

The carriage lias a front extension supported by a sliding 
bracket for use at the full swing of the lathe. By extend¬ 
ing the bed to its full length and supporting it with the jack- 
screws shown it is possible to turn long shafting. The lathe 
shown is triple-geared, and the size and weight of the heads 
and carriage are such that ordinary work can be done effec¬ 
tively at the largest swing. 

50. Two-Spindle Lathes. 

The lathe shown in Fig. 41 offers another solution of the 
problem of killing a large bird and a small bird with the same 
stone. This machine is designed on the same general lines as 
a lathe of the smaller swing but with all its parts unusually 
massive. Supplementary head and tail spindles are provided 
above and to the rear of the ordinary spindles, such as to give 
about double the normal swing above the bed. A supple¬ 
mentary tool post and the necessary gearing for the head 
completes the equipment. When in use for ordinary work 
the machine is to all intents and purposes a 26-inch lathe, the 
supplementary parts being entirely out of the way. When 
used at its full capacity it is a 48-inch lathe from head spindle 
to foot spindle, not so heavy nor so strong, perhaps, as the 
standard 48-inch machine, but strong enough for emergency 
work. It will be noticed that at the larger swing the face 
plate is directly geared. 


51. Reduction or Roughing Lathes. 

In shops where large quantities of heavy work are done, 
a simple lathe of unusual weight and power in proportion to 









26-INCH AND 48-INCH DOUBLE SPINDLE LATHE 













SPECIAL LATHES 


101 


its swing is a useful tool. Such a machine is to have a 
limited range ol work, but it is to do that work in less time 
than is possible on the standard all-round machines. 

I he Draper 18-inch reduction lathe is driven by a 6-inch 
double belt, and has four changes of back gears in the head 
and two speeds available from the countershaft, giving ten 
speeds in all. 1 he lathe is adapted to turning steel from one 



Fig. 42. 

ROUGHING LATHE. 

The II. K. Le Blond Machine Tool Co., Cincinnati, Ohio. 


inch to six inches in diameter, and is intended particularly 
for use with self-hardening steel tools. 

Another lathe of this type is shown in Fig. 42. The belt 
power is not as great, apparently, as in the preceding machine, 
there being four steps on the cone. The heads and spindles, 
however, are made heavier than usual, and the ways are 
widened to give more support for the carriage. Special pains 
have been taken with the carriage and the tool-holders to 
have them rigid enough for the work the lathe is expected to 
do. The high-speed lathe illustrated in Fig. 3 7 is also an 
example of this type of machine. 

















102 MODERN AMERICAN MACHINE TOOLS 


52. Stud and Bolt Lathes. 

Somewhat akin to the reduction lathe in simplicity and 
adaptation to special work are the single-head stud lathes, as 
they are usually termed. This latter type of machine is in¬ 
tended for plain turning on short pieces which are to be made 
in large quantities. Such a lathe is well adapted for work 
which is too long to be successfully handled on the turret 
lathe. Like the reduction lathes it has a large belt contact, 
but unlike them has no back gears. The screw-cutting 
mechanism is left out, thus doing away with complication of 
gearing ; and the beds are short, ranging from 4 to 6 feet. The 
lathe usually has an automatic stop on the feed motion so that 
it may be used for turning up to a shoulder. 

53. Tool-Makers’ Lathe. 

Fig. 43 shows a type of lathe designed for use in the tool¬ 
room on work which calls for an unusual degree of accuracy. 
This machine makes the tools which make the work, and any 
error here would appear in the work, perhaps in a magnified 
degree. Lathes of this class are expensive and not intended 
for general use. The bearings of all sorts are generous in 
size and finished with special care. The lead screw is large 
in diameter, and has a very small limit of error. The 
carriage is guided by one large V at the front and a flat bear¬ 
ing at the back to ensure good alignment. The lathe has 
a large number of special attachments, which fit it particularly 
well for the varied service of the tool-room. 

54. Facing Lathes. 

For short work of large diameter this class of lathe is well 
adapted. The tailstock and the screw-cutting mechanism 
are omitted, and the work is held entirely by the clutch or 
face plate. Two tool-posts are used, making it possible to 








SPECIAL LATHES 


103 


tin ii and face work at the same time. The carriage is wide 
j an d heavy, with special 1 -slots for attaching the tool holders. 

the cone pulleys on the spindle and those used for driving the 
i feed are larger than usual and have steps for wide belts, 



Fig. 43. 

TOOLMAKER’S LATHE. 

The Pratt and Whitney Co., Hartford, Conn. 


thus making it possible to take a full cut at the extreme 
swing of the lathe. 

It is but fair to remark, however, that vertical boring 
mills are to a large extent replacing lathes for this class of 
work. 


55. Railroad Machinery. 

Besides the special lathes which have so far been 
mentioned, there are others which are restricted to an even 



















104 MODERN AMERICAN MACHINE TOOLS 


narrower range of work and have no place in the general 
machine shop. But brief mention can be made of such in a 
general treatise. 

The manufacture of locomotives and other railway machinery 
has resulted in the specialising of tools to an extent seldom 
seen elsewhere. The enormous number of locomotives and 
car axles made in this country has necessitated a special lathe 
for this class of work. Like the roughing lathes which have 
been shown, this machine is massive and adapted for heavy 
cuts at a high speed. To permit of the use of two tools, the 
axle turns on two stationary centres and is driven by a 
rotating head in the middle. In every sense of the word 
this is a special machine. 

The same may be said of car-wheel and driving-wheel lathes, 
which are adapted only to this one class of work. Fig. 44 
illustrates a 100-inch driving-wheel lathe and needs but little 
explanation. The size of the wheel to be turned makes it 
necessary to drive from both ends of the axle at once. The 
two large face-plates shown are accordingly driven in unison 
by gearing with one pinion shaft underneath. The tool-posts 
are also in duplicate and especially designed for the very 
limited service of the lathe. 


56. Miscellaneous. 

The shafting lathe is a machine which is of the same 
special character as railroad machinery and not adapted for 
use in general shops. Its extreme length and its lack of 
adaptability render it a sort of white elephant in the ordinary 
machine shop. On the other hand, it would be foolish to 
think ot turning shafting in the old-fashioned machine at a 
sacrifice of both quality and quantity of work. 

Hie speed lathe or hand lathe used for finishing and 
polishing work at a high speed is so simple in its construction 
as to need no description. 





Niles-Bement-Pond Co., New York. 













I 06 


MODERN AMERICAN MACHINE TOOLS 


57. Turret Machinery. 


The necessary duplication and interchangeability of parts 
on small machine work, has led to the cjuite geneial adoption 
of turrets carrying several forming tools, which are used in 
succession on the piece to be finished, this method peimits 
of great speed in handling and machining the work, and at the 
same time ensures accurate duplication of parts. 

The turret may be used as an attachment to an engine 


i:r 

)\ 

u; 


11 

11 


1 



Fig. 4o. 


ENGINE LATHE, WITH TURRET ON CARRIAGE. 


The K. K. Le Blond Machine Tool Co., Cincinnati, Ohio. 


lathe, in which case it may take the place of a tailstock or 
may be fastened to the carriage. In the former case the 
usual carriage is retained, and its tools may be used as in 
ordinary work. In place of the foot block or tailstock a shoe 
is clamped to the ways of the lathe, and on this moves the 
slide carrying a turret with sockets for six tools. The slide 
is operated by a turnstile, and the turret is turned either 
by hand or automatically. The power feed for the turret 
mechanism is independent of the carriage feed, so that both 
sets of tools may be operated at once, each with the feed best 
adapted to the work. In selecting a lathe for this class of work 
special attention must be paid to the main spindle, since these 




































I'jpt 

ised 


>erm 




ck 

dl 

as 

si 

tf 

slid 

tl 

rr 

)0l 

)e 

01 


ei 


TURRET LATHES 107 

re subject to much greater wear than when the lathe is used 
for ordinary turning. 

Eig. 45 shows an 18-inch engine lathe equipped with 
turret mechanism on the carriage, a special cross-slide being 
rovided on which the turret revolves. This lathe has the 
usual longitudinal feed, power cross-feed and screw-cutting 
attachments, and is well adapted for short chuck-work where 
turret tools take the place of the compound rest. 

In this machine, as in that just described, either the turret 
machinery or the usual tailstock and compound rest may be 
employed, making it a sort of combination tool. Such a lathe 
is useful in small shops doing miscellaneous work, where the 
expense of separate turret machines might be prohibitive. 


58. The Turret Lathe. 

The application of turret attachments to engine lathes is 
profitable under the circumstances just mentioned, but must 
be regarded as a compromise. Wherever there is work 
enough to keep a turret machine running continuously, it is 
better to install a lathe specially designed for this class of 
turning. A good example of the turret lathe pure and simple 
is shown in Fig. 46. A machine using so much oil as is 
necessary in forming and chucking steel should have a pan to 
catch the drip. Stiffness and perfect alignment are essential 
in turret work, hence the casting of lieadstock, bed and pan in 
one piece. Reversing the cone pulley and putting the small 
step in front also makes it possible to stiffen the headstock at 
this point. For similar reasons the turret slide is located 
directly on the bed of the lathe, which is specially designed for 
this purpose. The lathe shown will take stock up to 1 inch 
in diameter and finish up to 10 inches in length, fig. 4/ 
shows clearly the shape of slides used, which are such as 
to ensure uniform wear on flat and on bevelled surfaces, and 
adjustment without loss of alignment. A turnstile is used 
for moving the slide, but a lever may be substituted when 








1-INCH x 10-INCH TURRET LATHE 





















TURRET LATHES 


109 


) 


i 

i 



desired. The steel rods which act as stops for the turret 
slide may be seen in either figure ; as the turret turns into 
position an arm or lever hinged to the slide is moved auto¬ 
matically by a cam so as to strike the end of the proper rod. 
The locking of the turret itself takes place directly under the 
tool in use at the time, as is right. The indexing mechanism 
for the turret can be 
readily thrown out of 
gear when it is de¬ 
sired to use only two 
tools. Without any 
sacrifice in conveni¬ 
ence of operation, the 
turret and slide seem 
to have the least 
number of pieces and 
joints possible and 
consequently to be 
rigid and accurate. 

A double cross¬ 
slide is used with form¬ 
ing and cutting-off i n. 

tools, one in front and 
one behind the work. 

The slide can be lo¬ 


Traverse Section of New Model Turret Lathe 
at Centre of Turret. 

The Pratt and Whitney Co. 


cated anywhere between headstock and turret slide and 
clamped to ways the same as those shown in Fig. 47. The 
tool-posts have each two screws for clamping the tool, and are 
so made that the tool may be raised or lowered bodily or set 

at an angle. 

Two means are provided for operating the cross-slide, a 
lever connected to pinion and rack for use with cutting-off’ or 
narrow tools and a hand-wheel turning a screw for wide tools 


which require a slow feed. 

The collet or chuck for holding the tool is operated by the 
same lever that advances the rod, and is so constructed that 









































































110 MODERN AMERICAN MACHINE TOOLS 

in closing it does not move the work forward or back. The 
feed for the rod has double the throw of the closing mechanism 
so as to feed long work with but one motion of the lever. 

Oil is fed from the pan to the tools by a rotary pump at 
the rear of the head stock. 

59. Hollow Hexagon Turret. 

Fig. 48 illustrates a somewhat larger and heavier machine 
than that just described. This lathe is triple-geared, has a 
swing of 16 inches over the ways, and will handle 2-inch round 
stock up to 24 inches in length. The head is cast solid with 
the bed, and the latter rests on a line bearing at the turret 
end so that the machine will adapt itself to irregular founda¬ 
tions without springing. The jaws of the chuck and the rod 
feed are operated by the longer vertical lever in front of the 
head. The roller feed for the stock can be used when the 
machine is running or when it is at rest. 

The turret is of the hollow hexagon type turning on a 
saddle which is gibbed directly to the bed of the machine. 
This saddle slides on large Vs, and is fed automatically by 
means of a rack located in the top of the bed directly under 
the cutting tools so as to avoid twisting strains. The three 
feeds available are controlled by a nest of gears, and the 
changes can be made without stopping the machine. The 
hollow hexagon form of the turret permits of securely fasten¬ 
ing the several tools from the inside and leaves the outside 
free for other mechanism. The motion of the turret is auto¬ 
matic, being controlled by the backward motion of the slide 
or saddle. 

The stops for the turret slide are located on the front of 
the machine in such a position as to be free from chips and 
dirt, and so arranged as to furnish three different stops for 
each face of the turret. 

No carriage is used with this type of lathe, since the style 
of turret described permits of attaching all turning and 




ft I 


The Warner and Sivasey Co., Cleveland, Ohio. 




























112 


MODERN AMERICAN MACHINE TOOLS 

cutting-off tools directly to turret. In the form of cutting- 
off tool used, the cross-slide is manipulated by a lever at the 
top having adjustable stops at the bottom. The oil spout in 1 
this machine is carried by the turret slide so as to always be 
above the cutting tool, and the oil flows continuously, whether 
the machine is running forwards or backwards. 


60. Flat Turret Machine. 

The machine shown in Fig. 49 differs from those already ; 
described in the shape of the turret, which is of the so-called j 
Hartness or fiat type. It consists of a flat, circular plate j 
mounted on a low saddle and carrying the various tools and 
tool holders on its upper surface. The principal advantage 
claimed for this type of turret consists in the fact that the 
tools do not overhang but have an unyielding support directly | 
under the cut. Furthermore, the turret plate itself is secured 
to the saddle by an annular gib, thus clamping it rigidly to the 
saddle at all points. The turret is automatic, turning as the 
tool clears the work, and may be so set as to skip one or more 
of the indexing positions when desired. The locking bolt is 
on the outer edge directly under the cutting tool. There are 
six feed-stops for the saddle, or one for each face of the turret. 
These are located on the top of the bed. The saddle slides on 
Vs, is gibbed to the outside of the bed, and has a power feed 
operated by a feed rod and rack somewhat similar to those of 
an engine lathe. 

Back gears and triple gears are furnished for the head, 
giving either 4 to 1 or 16 to 1 ratio as desired. The gearing 
is in the head below the main spindle. As may be seen from 
the cut the cone has but three steps, and these are unusually 
wide, giving good belt power. The machine is intended to 
handle work up to 2 inches in diameter and 24 inches long, 
but it can be used for chucking pieces up to 14 inches in 
diameter. The general arrangement of bed and headstock 












IL 


FLAT TURRET MACHINE. 





























114 MODERN AMERICAN MACHINE TOOLS 




are more like those of an engine lathe than most of those 
shown in this chapter. 

The collet or chuck will hold any shape of rough stock 
firmly, and the roller feed permits of advancing and gripping 
the rod without stopping the machine. 

The feed is actuated by the power of the machine, and is 
set in motion by the same lever which controls the chuck. 
This lever may be seen at the front of the head in Fig. 49. 

The machine just described is particularly well adapted to 
turning and threading large studs and bolts cut directly from 
the rough stock. Samples of work done by the regular outfit 
of tools accompanying the machine include studs of machinery 
steel from to If inches in diameter and varying in length 
from 3 to 6 inches, which were finished in from 7 to 20 
minutes each. The work on each stud included turning: to four 
different diameters and cutting one or more screw threads. 
Bolts from 2 to 6 inches long and J to f inch in diameter 
have been finished in from 2 to 7 minutes each. A limit of 
variation in size of one quarter of a thousandth of an inch is 
practicable. 

The characteristics of turret machinery which have made 
such speed and accuracy possible are in the main as follows :— 
Rigidity in turret, tools and head, coupled with good alignment. 
Automatic setting of turret and of carriage in the exact posi¬ 
tion for work. Simplicity in the movements required for 
setting and clamping stock. The possibility of making speed 
and feed changes without stopping the machine. Last, but 
not least, the free supply of oil to the cutting tool so as to 
flood the work and carry away heat and chips promptly. 


6i. Automatic Lathe or Chucking Machine. 

I lie turret lathes so far described are intended for cutting 
up and forming steel rod into studs, collars, sleeves, etc., and I 
are expected to handle material up to 2 inches in diameter. 
Turret work is not by any means confined to these limits, and 






TURRET LATHES 


115 


it lias been found just as profitable to turn forgings and 
castings of a larger size in a similar manner. 

Lathes for this latter class of work are frequently called 
chucking machines, since the separate pieces operated on are 
usually held in a chuck and finished inside and out. A heavy 
machine of this type is capable of machining castings 24 inches 
in diameter. The use of wide forming or shaving tools 
necessitates massive construction and powerful gearing. The 
bed must have unusual depth and weight with a head cast 
directly to the bed. One such machine made by the 
American Turret Lathe Co. has four changes with double 
gearing, besides two with quadruple, making six in all, the 
ratios varying from 5 to 83. 

In the quadruple gearing a steel pinion engages directly 
with the rim of the chuck. The saddle is gibbed to the bed 
of the lathe and has unusually long bearing surfaces. It can 
be operated by a hand-wheel in front of the machine, but when 
in use is moved by a power traverse having a speed of 25 feet 
per minute. Eight different feeds are provided, and screw 
threads can be cut from 2 to 30 threads per inch. 

The turret is a hollow octagon with one side cut away for 
the cross-slide, which carries a tool-post. There are five tool 
holders on the turret itself, and several supplementary holders 
are used above the work. This lathe is well adapted for 
machining castings up to the full swing of the chuck. 

Some idea of the capacity may be obtained from consider¬ 
ing a cast fly-wheel Ifi inches in diameter finished in such a 
machine in one and a half hours, or one-third ot the time 
required to finish on an ordinary engine lathe. Piston heads, 
stuffing boxes, gears, cone pulleys, etc., can be finished com¬ 
pletely and in much less time than by former methods. 

62. Turret Tool-Post Lathe. 

The machine illustrated in Fig. 50 is intended for 
handling the very largest work which it is practicable to 


116 MODERN AMERICAN MACHINE TOOLS 

finish in a turret lathe and will swing pieces 34 inches in 
diameter. A gap lathe of this same size swings 50 inches in 
the gap. 

The peculiar features of this lathe are the inclined posi-, 
tion of the turret and the use of an intermediate turret 
capable of carrying four tools. 

The bed and headstock are cast in one piece ; the spindle 
is very large, having a 4^-inch bore, and the cone is fitted 
for a 6-inch belt. The spindle has a friction back-gear, 
operated by the upright lever shown in front, and a pinion 
gearing direct to the chuck for unusually large work. Like 
the lathe described in the preceding article, this machine is 
intended principally for operating on castings or forgings held 
in the chuck and not for cutting from the solid stock. 

Both the tool-post carriage and the turret saddle slide 
on Vs similar to those of an engine lathe and are secured by 
gibs underneath the ways. The main turret is hexagonal 
and, as shown in the cut, so inclined as to throw the tools in 
front up out of the way of the operator. The size of the 
turret permits of the use of quite elaborate turning and form¬ 
ing tools for various classes of work. 

The traverse of the turret slide in the machine illustrated 
is 72 inches, and it can be moved by hand or by power. 
There are four reversible feeds for each carriage, and when 
desired a power quick-return is furnished for the turret 
slide. 

Independent stops are provided for each of the six faces 
ol the turret, and also for each of the four tools on the inter¬ 
mediate carriage. 1 his latter is a feature somewhat different 
from any so far described. It is a carriage similar to that of 
the engine lathe with longitudinal and transverse power 
feeds. Instead of the ordinary tool-post it is equipped with 
a turret having places for four separate tools and capable of 
being turned on a vertical axis. The tools in this turret can 
be adjusted independently for height, and are well adapted 
for turning and facing the outside of large work, while the 







■ 


Gisholt Machine Co., Madison, Wisconsin. 














118 MODERN AMERICAN MACHINE TOOLS 

other turret is used for boring and for facing nearer the 
centre. The four tools on the tool-post in combination with 
the six on the large turret make it possible to finish quite 
complicated castings or forgings without change of tools. 
The power of the lathe is such that wide shaving cuts can be 
taken without difficulty. 

The machine seems well suited for finishing such pieces 
as pistons, cylinder heads, flanges, couplings and pulleys up 
to the limits given by the size of the machine. 

63. Forming Machines. 

The lathe generally known as a forming machine is one in 
which the tool is as wide as the work is long and reduces the 
latter to the required shape at one operation. While it is 
evident that the work can be rapidly finished in this way, it 
is also manifest that the machine must be powerful, and that 
the work must be securely held. Fig. 51 illustrates a 
machine of this character intended for unusually heavy work, 
and capable of forming from the rough bar pieces 3 inches in 
diameter and 5 inches long. 

The machine is massive in construction, has a long and 
large spindle, and carries a cone with wide steps, but gearing 
is unnecessary with the sizes of stock used. To prevent 
overhang and ensure firm support to the work, the end of the 
spindle itself is enlarged and threaded inside to receive the 
collet which grips the stock. The chuck is thus practically 
a part of the spindle. The carriage of the machine carries 
a slide on which are mounted the forming cutters, one for 
roughing and one for finishing. An independent slide carries 
a cutting-off tool. 

The turret slide can be equipped with a drilling attach¬ 
ment as shown in the cut, or with the ordinary turret. By 
using the drilling attachment an independent speed may be 
given to the drill through the overhead gearing shown, and 
thus forming and drilling be performed at the same time 



HEAVY FORMING MACHINE. 























120 MODERN AMERICAN MACHINE TOOLS 


and at the best speed for each. This machine is intended 
primarily for bicycle and automobile hubs and hollow steel 
work of a similar character. 


64. Automatic Screw Machine. 

The machines so far noticed have been partially automatic, 
but such as to require the attendance and attention of the 
operator. 

For the production of large numbers of small parts cut 
directly from the bar it is desirable to have a machine which 
is entirely automatic; which will take a bar of steel and cut 
it up into finished pieces, only stopping when that particular 
bar is entirely used, thus making it possible for one operator 
to attend several machines. 

The Cleveland automatic screw machine is of this 
character, and is so far differentiated from the ordinary lathe 
as to really belong to another class. This particular machine 
is intended for handling work up to 2f inches in diameter and 
6§ inches long, has six holes in the turret, and two tool-posts 
on the cross-slide. The head spindle is at the left of the bed, 
and is driven by gears from a reversing countershaft at the 
rear, so as to eliminate any belt pull on the main bearings. 
The pulleys on the countershaft are arranged somewhat as 
are those on a planing machine, so that the automatic shifting 
of the belt reverses the machine and gives a quick return for 
screw cutting. 

If bar stock is used, the feed and chucking arrangements 
are automatic. If small castings or forgings are to be 
handled, a magazine can be attached which will handle the 
pieces and only needs to be kept filled. 

The turret consists of a horizontal cylinder mounted 
eccentrically in heavy bearings at the right of the machine 
and bored with six holes for tools in the end. The locking 
circle is larger than the tool circle, giving rigidity to the 
tools. The return of the turret automatically revolves it 


TURRET LATHES 


121 


into a new position as soon as the tool is clear of the work 
by means of the cam on the spindle. The cross-slide is 
fitted for two circular cutting-off or forming tools and is 
also automatic. 

In fact the machine, as its name implies, is entirely auto¬ 
matic in its character, and is therefore particularly useful for 
the indefinite production of small duplicate parts. 

It is possible in this machine to have different feeds for 
the different tools in the turret when desired. 

65. Automatic Chucking Machine. 

A lathe, automatic in its character but adapted more 
particularly for chucking larger work, is shown in Fig. 52, the 
cut illustrating a machine which will swing pieces 17 inches 
in diameter over the ways, and will finish over the carriage 
pieces 10 inches in diameter and 5T inches long. 

By means of the longer lever in front of the head the 
chuck may be operated on either outside or inside grip, 
without stopping the machine. 

The spindle is driven either by gears or belts from an 
automatic countershaft at the rear in such a way that the 
reversing is performed automatically, and that a change h om 
fast to slow speed or the reverse may also be effected by the 
machine itself. For instance, if a piece is to be drilled and 
then turned, the machine will change automatically from the 
high to the low speed as the tools change. 

The ordinary turret slide is used, operated in this case by 
the cam drum shown underneath. A set of cams is furnished 
with each machine suitable for doing all ordinary work up to 
the capacity of the turret. 

The lathe is usually furnished with a cross-slide (not 
shown in the cut) carrying two tool-posts and entirely 
automatic in its action. By properly arranging the tools 
it is possible on some work to have from five to eight cuts 
simultaneously; and as the machine is automatic in all its 




AUTOMATIC CHUCKING AND TURNING MACHINE 







TURRET LATHES 123 

cutting operations, one workman can attend to several 
machines. 

Hie output ot such a tool is, ot course, far in excess of 
that ot the engine lathe. As an example of its possibilities 
an instance may be cited where thirty clutch pulleys of cast 
iron 10 inches in diameter by 2-inch face were finished in ten 
hours, or an average of twenty minutes each. This included 
turning the rim, boring and facing the hub, and cutting a key¬ 
way. 

66. Vertical Turret Machine. 

The vertical machine bears about the same relation to the 
ordinary turret lathe that the vertical boring mill bears to the 
engine lathe. In fact, it is a small boring mill carrying a 
turret on the cross-rail. 

The machine is intended for chucking castings and forgings, 
and possesses the usual advantages of vertical machines in the 
ease with which the work may be handled and inspected and 
in the rigidity of the chuck and spindle. 

In the Warner and Swasey machine the main driving gear 
is cast to the spindle, and the line of centres of gear and 
spindle is directly under the line of travel of the cutting tool. 
There are three steps on the driving cone, two changes in the 
friction gearing operated by a lever, and two speeds to the 
countershaft, making twelve in alh 

The turret is mounted much the same as the tool-post of 
a boring* mill, the turret slide having a vertical movement on 
the saddle, the latter having horizontal travel on the cross¬ 
rail, and the rail a vertical adjustment on the housing. The 
saddle can also be swivelled through an angle of 30 degrees 
as on a planer or boring mill. 

Both slides are fed by power when necessary, and each 
has eight changes of feed. Automatic stops are provided 
for tripping the feed at any desired point. All gearing is 
protected from dirt and chips by iron casings. 









124 MODERN AMERICAN MACHINE TOOLS 



. Power and Capacity. 


Perhaps no other improvement of modern times has 
brought about a greater increase of output than the introduc¬ 
tion of turret machinery. The multiplication of cutting edges 
in action at one time is one feature of the change, many of the 
lathes described being capable of performing several distinct 
operations at the same time. This characteristic is not 
peculiar to turret machines, but is common to drilling, boring, 
and planing machinery. The use of forming or shaving tools, 
which give a complete profile or outline at one cut, is another 
feature which has given the turret lathe an advantage over 
ordinary lathes. Add to the advantages above mentioned the 
automatic or semi-automatic action of most turret machinery, 
and you have a combination which has made it possible for 
this class of lathe to outstrip all competitors in quantity and 
quality of output. The fact that recent improvements in other 
classes of machinery along these same lines has enabled them 
in some cases to approximate to the production of the turret 
lathe is rather an argument for than against the lathe. Let 
it be remembered, however, that the advantages enumerated 
are dependent largely on the manufacture of large numbers of 
duplicate small parts, and that unless a company has reached 
the point where it builds its machines by fifties or by 
hundreds it will not get the full benefit of this method of 
manufacture. An increase of output cannot be obtained 
without a corresponding increase of power, since it requires 
just about so many horse-power to remove a hundred pounds 
of steel in an hour whether it is done by one tool or several. 
For this reason the turret machine is somewhat in the same 
class as the high-speed reduction lathe as regards power 
required to drive it. 

Machines like those illustrated in Figs. 49, 50, and 51 with 
their wide pulleys and double gearing, may be expected to 
require about the same driving power as the lathes shown in 
Figs. 37 or 42. 


31 ' 

St' 

fo 

ci 


n 

1 * 

la 

IT 

i> 










TURRET LATHES 


125 


Electric transmission has been employed to drive this type 
of machinery, but usually in groups rather than by independent 
motors. As the automatic machines for producing small 
steel parts directly from the bar are usually run in groups of 
from two to six machines attended by one operator, the 
circumstances are favourable for the use of one countershaft 
with friction clutches, driven by a single high-speed motor. 

Some of the larger chucking and forming machines can he 
run, however, by independent motors, since from 2 to 5 
horse-power is likely to be required for each lathe. The 
lathe shown in Fig. 50 can be equipped with a direct-geared 
motor located on the bed back of the headstock, a large gear 
being substituted for the cone pulley on the spindle. 







tl 

I) 

e 

' E 

1 

CHAPTER V | 

k 

{ 

BORING MILLS, VERTICAL AND HORIZONTAL i 

2 

68. Vertical Boring and Turning Machinery. 

In the last chapter reference was made to vertical turret 1 
machinery, and some of the advantages of that class of tools 
were mentioned. When pieces of considerable length of rela¬ 
tively small diameter are to be bored or turned, the superi¬ 
ority of the horizontal lathe cannot be disputed, the work 
being more easily handled and inspected when in this position. 
On the other hand, when castings or forgings of relatively 
large diameter are to be chucked and finished various diffi¬ 
culties present themselves. 

The tailstock is now a superfluity, and the carriage and 
tool rest are no longer adapted to the work. There is diffi¬ 
culty in supporting the work while attaching it to the face 
plate, and when it is finally in place, the heavy mass of 
chuck and casting overhangs the bearings without adequate 
support and tends to cause springing and vibration. There 
is, moreover, difficulty in seeing the cutting tool on inside 
work, and the chips are continually in the way. 

These various inconveniences have led to the more 
general adoption of the vertical type of machine, until at the 
present time the former method of chucking large work is 
rarely seen. 

The advantages of the vertical boring and turning mill 
over the engine lathe for handling work of large diameter 

may then be summarised as follows :—Greater ease in placing 

126 







BORING MILLS 


127 


the work upon the machine and in supporting it while it is 
being clamped in position. Firmer support under the influ¬ 
ence of its own weight and the pressure of the cutting tools. 
Better adaptation of the tool slides and supports for per¬ 
forming the required operations. 

Boring mills may be classified according to the nature of 
the uprights or housings which carry the tool slides, thus :—1. 
Single-post machines such as that shown in Fig. 53, intended 
for relatively small work or for boring without turning. 2. 
Machines with two posts or housings used for both turning 
and boring, and ranging in size from 3 feet to 20 feet 
in diameter. 3. Machines with adjustable housings used for 
the very largest work, and frequently capable of swinging 
30 feet in diameter. 

69. Single-Post Machines. 

The vertical turret machine described in Chapter IV. 
is an example of a boring and turning mill with but one 
housing. 

O 

Most machines of this class are equipped with a turret on 
the tool slide since they are intended for small work. If 
desired, the ordinary tool holder could be substituted without 
changing the design of the machine. Mills of this character 
are usually built to swing not more than 30 inches. 

Fig. 53 shows a turret mill intended for boring alone, 
there being no cross-rail and consequently 110 horizontal 
movement for the tool. The machine is driven by a step 
cone without back gears, and the table is supported by a step 
bearing at the foot of the spindle and a journal bearing above. 
The turret has four holes fitted for shanks of drills or boring 
bars and has a vertical movement of 25 inches. The feed 
can be moved by hand, or by means of the worm and gear 
shown at the top of the mill. The general design of the 
frame is good, and the wheels and levers are conveniently 
arranged for the use of the operator. 






128 MODERN AMERICAN MACHINE TOOLS 


70. Machines with Two Housings. 


This is the standard type of vertical boring and turning 




I 






I 



Fig. 53. 

30-INCH TURRET BORING MILL. 

Niles-Bement-Pond Co., New York. 


mill, and as such merits a detailed description. Such 


a 












BORING MILLS 


129 


machine consists of the following principal parts: ( a ) the 
revolving table and its supports; ( b ) the uprights or hous¬ 
ings ; (c) the cross-rail; (cl) the tool-slide or head ; (e) the 
driving mechanism ; ( / ) the feed gearing. 

As may be seen from the illustrations in this chapter, the 
boring mill resembles the planing machine rather than the 
lathe, and may be comprehensively described as a planer in 
which the table has a rotary instead of a sliding motion. 
Th is change in the cutting motion necessitates other modifi¬ 
cations which will be attended to in the proper place. 


71. The Table. 

Like the spindle of a lathe, the table of a boring mill is 
the main feature in the design, for upon its accuracy depends 
the question of good or bad work. It should revolve easily 
and smoothly at high speeds, and should be rigid and steady 
under the wide cuts and heavy pressures incident to turning 
large work. 

O 

The spindles of relatively small machines such as that 
illustrated in Fig. 53 are sufficient in themselves for the 
support of the table, but care is taken that the driving pinion 
may engage the gear as nearly in line with the cutting tool 
as possible, to eliminate any torsion on the spindle itself. 
This same principle has been before noticed in connection 
with the direct gearing on large lathe chucks. 

The tables of larger machines require additional support 
when used for turning large work, to prevent springing 
downward under the pressure of the tool. 

For mills of moderate size the arrangement shown in 
Fig. 54 has been found accurate and durable and is peculiar 
to the make of mill indicated. The spindle proper has two 
cylindrical journals of different diameters, and an adjustable 
collar at the lower end to prevent any tendency to lifting of 
the table. Directly under the table is a larger conical bear¬ 
ing to take the vertical pressure. 

o i 

I 






130 MODERN AMERICAN MACHINE TOOLS 


In the 37-inch machine shown in the figure the maximum 
pressure on the conical bearing in the most extreme case 



Fig. 54. 

37-INCH TABLE AND SPINDLE. 

The Billiard Machine Tool Co., Bridgeport, Conn. 


I 

would be only 46 pounds per square inch, while under I 
ordinary circumstances the pressure would be much less than 
this. 

The conical bearing has the further advantage of being 
























BORING MILLS 


131 


self-centering as it wears. Constant lubrication is effected 
through the stationary pipes shown in the cut. The table is 
driven by means of a small bevel pinion engaging a gear 
near its outer circumference. There is this disadvantage in 
the use ol bevel gearing that it has a tendency to lift the 
table at the edge. The makers of the mill shown in Fig. 54 
claim that this has been eliminated by the shape of tooth 
adapted. 

The table of the machine shown in Fig. 55 is driven by a 
bevel gear on the outer edge. The vertical thrust is taken 
by hardened and ground-steel collars. 

The 51-inch mill illustrated in Fig. 56 also has its table 
driven by bevel gearing. In this machine there are two 
annular bearings for the table, one near the outer edge and 
one close to the spindle. In all the machines shown in the 
figures the spindle is hollow to allow chips to fall through 
when boring is done. 

In Fig. 57 no outer support for table is shown, and the 
vertical thrust is taken by a hardened steel step at the 
bottom which is submerged in oil. The driving mechanism 
consists of a bronze pinion on a vertical axis meshing with 
an annular gear just inside the rim of the table. This type 
of gearing seems to the writer the best for this purpose, since 
it does not tend to lift the table and will give a smoother 
motion under heavy cuts on account of the longer arc of 
contact between the teeth. 

On some machines advantage is taken of the use of both 
a spindle step and a table bearing to make the former 
adjustable as to height. It is then possible, by raising the 
step, to relieve the pressure on the annular bearing under the 
table when running at high speeds on light work and thus 
reduce the moment of friction. The machine shown in 
Fig. 58 has this adjustment. 

Worm gearing is used for driving the table on the 5 ft., 

6 ft., and 7 ft. mills of the make illustrated in Fig. 59. It is 
well known that the action of worm gearing is smoother and 








132 MODERN AMERICAN MACHINE TOOLS 

more continuous than that of spur or bevel gearing. For the 
high speeds used on the smaller machines this form of gear 


Fig. 55. 

37-INCH BORINC AND TURNING MILL. 

The American Tool Works Co., Cincinnati, Ohio. 


gives a smooth motion free from chattering. A ball-thrust 
bearing is used for the worm and the whole runs in a bath of 
oil. For larger machines and heavier work the worm gear is 
not available on account of its low efficiency and great end 
pressure. 













133 


BORING MILLS 

The diameter of the table is usually slightly less than the 
rated swing of the mill and the vertical capacity under the 
rail from two-thirds to one-half the swum. The vertical 
movement of tool spindle is about two-thirds of the latter 
dimension. For instance, a 6-ft. mill would have a height 
of about 4 ft. under the rail and a vertical travel of tool of 
about 30 inches. 

72. The Housings. 

The uprights of boring mills are in many respects similar 
to those of planing machines, being usually parabolic in out¬ 
line with flat front faces for the attachment of the cross-rail 
and connected together at the top by the top brace. 

The severest strain which can come upon a housing is 
when turning 1 work of large diameter and maximum height. 
There is then the full pressure of the cutting tool exerted at 
a point near the top of the upright just as when cutting large 
work in the planing machine. Side pressure of the tool also 
has the effect of springing the uprights to one side as in the 
planer. 

In the smaller machines the housings and the bed are 
usually one casting, as in Fig. 55. In machines of larger 
swing the uprights are bolted to the bed, either to the top as 
in Fig. 57, or to cheeks on the side as shown in Figs. 56 
and 59. 

The latter would seem the better way as securing more 
rigidity. The location of the uprights is far enough back to 
bring the tools over the centre of the table, and the distance 
between them is usually several inches less than the diameter 
of the latter. 

73. The Cross-Rail. 

As may be seen by reference to the various illustrations 
in this chapter, the cross-rail has the same general character¬ 
istics as in the planing machines. It is gibbed to the flat 
ways on the uprights and is raised or lowered by power, a 






134 


MODERN AMERICAN MACHINE TOOLS 

counterpart on the top brace being geared to both elevating 
screws and being driven by belting from the driving shaft 
below. Fig. 50 shows this arrangement clearly. The rail 



Fig. 56. 

51-INCH BORING MILL. 

The Baush Machine Tool Co., Springfield, Mass. 

must have wide bearing surfaces for the tool saddles, and 
must he braced at the rear to resist bending. The usual 
form is that of a box girder. The top way of the rail must be 
rectangular to hold the overhang of the tool heads, while the 
lower one is sometimes bevelled as in Fig. 57. 


























BORING MILLS 


135 


74. The Tool Heads. 

All boring mills of 37-inch swing and over have two heads, 
usually made right and left that they may be brought close 
together. The saddles are gibbed to the cross-rails and 
have means of adjustment for wear. The heads can be 
swivelled to any reasonable angle, and the rails are of such 
length that the tool can operate at the full diameter of the 
table when so swivelled. 

The tool bar or head itself is of necessity entirely different 
from the corresponding member on a planing machine. The 
principal function of the tool head on a planer is to travel 
horizontally on the rail for wide surface cuts. In the boring 
mill, on the other hand, the turning and boring which consti¬ 
tute the greater parts of the work are done by vertical travel 
of the tool, while the horizontal motion is only used for 
facing. 

It is therefore necessary that the tool bar should have 
ample bearing surfaces to resist wear, and that the bearings 
should have sufficient length to hold the tool firmly when it 
is at the lower end of its travel. A study of the various cuts 
will show how this has been accomplished. The bar itself is 
usually octagonal in cross section, with bearings on alternate 
sides, as shown in Figs. 55 and 57. 

It may, however, be rectangular, as in Figs. 58 and 59, or 
cylindrical, as in Fig. 56, with wing slides. The material 
used must be steel of the best quality, combining great 
strength and stiffness with good wearing qualities. 

In the machine shown in Fig. 55 two bearings are used, 
some distance apart, so as to resist the bending moment. 
These bearings are provided with caps to give compensation 
for wear. 

The bearing is in most machines continuous, either with 
one cap covering the whole bar, as in Fig. 57, or with two 
gibs, one on each side, as shown in Fig. 56. 

The vertical traverse is usually effected by a pinion 






136 MODERN AMERICAN MACHINE TOOLS 

engaging a rack on the tool bar. In the best machines the 
rack is cut directly in the solid steel of the bar. 

Nearly all the illustrations show a large wheel or turn¬ 
stile on the tool head by which the hand traverse is effected, 



Fig. 57. 

72-INCH BORING AND TURNING MILL. 

II. Bickford and Co., Lakeport, N.H. 

while the small wheel is used for throwing in the power feed. 
The great size and weight of the bars makes counterbalancing 
imperative. This is generally effected, as shown in Fig. 56 , by 
carrying one rope or chain over and under guide pulleys in 
front of the tool heads in such a way as to counterbalance 
both with one weight. The objection to this particular 





















BORING MILLS 


137 


arrangement is the fact that the rope is sometimes in the 
way of the hoisting chain from the crane. 

Fig. 57 shows how this difficulty has been met by keeping 
the chains back of the heads and cross-rail. 

The feed rods and screws are so arranged that either 
head may be fed independently in any direction. The feed 
mechanism will be discussed in another paragraph. 

Either head is usually so arranged that it may be run to 
the centre of the table and brought into exact alignment by a 
centre stop. One or both heads are fitted with a taper hole 
for receiving drill shanks, boring bars, etc. ; and when in the 
centre position this hole is exactly in line with axis of table, so 
that a boring bar or reamer may be supported at its lower end. 

It should be possible to clamp the tool slide at any 
required height when the machine is used for facing large 
work. 

75. The Feed Mechanism. 

In most boring mills the two heads have independent 
feeds, both horizontal and vertical, so that either may be 
used without any reference to what the other is doing. This 
is clearly shown in Fig. 5G, where the machine has four 
independent rods, two for each head, driven from opposite 
ends of the cross-rail. In Fig. 55 the four rods are seen to 
extend entirely through the rail and to be driven by gearing 
on the right end. Reference to the various illustrations in 
this chapter will show that both these arrangements are 
common. 

On the larger machines provision is made for throwing 
out the power feed, so that rapid traverse of the saddle on 
the rail may be effected by means of a rack and pinion 
motion, similar to that on the carriages of engine lathes. In 
fact, the manner of controlling the saddles and heads on this 
class of machine is so nearly identical with that used for opera¬ 
ting the carriage and tool post of an engine lathe as to 
render detailed description unnecessary. 


138 MODERN AMERICAN MACHINE TOOLS 

The feed gears on the end of the rail are driven by a 
vertical rod splined its whole length. It is in the driving of 
this rod that we find considerable variation among the several 
machines represented. 

The mill illustrated in Fig. 56 has the Hendev-Norton 
system of gearing, the same as used on the lathes of that 



Fig. 58. 

10-FOOT BORING AND TURNING MILL. 

Niles-Benient-Pond Co., New York. 

name (see Fig. 30), and in this way gets fifteen changes of 
feed, either of which is instantly available. This makes it 
possible to do thread-cutting on the machine when desired. 

The mill shown in Fig. 57 has cone pulleys and belts for 
making feed changes, while in the machine illustrated in Fig. 
59 a slotted feed plate or crank is used for this purpose. A 
Bullard 42-inch boring mill is equipped with one turret head, 
and has its feed mechanism driven by two sets of gearing 
located on either side of the machine and entirely indepen- 


















BORING MILLS 


139 


dent of each other. Ten changes of feed can be obtained 
with this machine, the ratio of maximum to minimum being 
about 24 to 1. 

On the other hand, the mills represented by the Figs. 55 
and 58 have a friction-feed device. This is shown so clearly 
in Fig. 55 as to need little description. The advantages 
claimed for this device are ease of adjustment when the 
machine is in motion, and the possibility of finer variations. 
Some builders object to it on the ground that it is not power¬ 
ful enough when the machine is taking heavy cuts, and that 
it does not give a sufficient range of feeds. It would seem to 
be particularly well adapted to light and rapid work, being 
more readily adjusted than the geared feed. 

76. The Driving Mechanism. 

As has already been noticed, the table may be driven by 
bevel, spur, or worm gearing, and this fact causes considerable 
variation in the general arrangement of the driving gear. 

The first and last methods mentioned permit of direct con¬ 
nection between driving shaft and table, while the spur gear¬ 
ing necessitates the employment of an intermediate shaft as 
shown in Fig. 57. 

The usual arrangement, especially for the larger mills, is 
to have the shaft at the side as in Figs. 57, 58, and 59, while 
in the smaller sizes the shaft is at the rear, as may be seen by 
reference to Figs. 55 and 56. The driving cone will have 
from four to seven steps depending upon the size of mill, and 
both double and triple gearing may be introduced. For 
instance, the 42-inch Bullard mill before mentioned has ten 
changes of speed, while the large 12-foot machine illustrated 
in Fig. 59 has thirty-six. 

77. Electric Transmission. 

The location of the driving shaft on a boring mill makes 
the application of electric motors particularly easy, and the 
fact that such mills are relatively large machines consuming 




140 


MODERN AMERICAN MACHINE TOOLS 

a considerable amount of power, points to tlie economy of 
independent motors. 

The simplest and cheapest method of attaching the motor 



Fig. 59. 

EXTRA HEAVY 12-FOOT BORING AND TURNING MILL. 

Betts Machine Co., Wilmington, Del. 


is probably that in which a constant-speed motor is belted to 
an overhead countershaft, and the ordinary mechanical speed 
control is not disturbed. 


















BOEING MILLS 


141 


As in the applications which have already been noticed, 
the constant-speed motor has the advantage of simplicity and 
cheapness, since a small, high-speed unit may be employed. 
The desirability ol electric speed control in operations involv- 
ing gradual changes ol speed has already been alluded to. 
TV here shop space is limited the belted arrangement is 
objectionable. 

Under these circumstances the variable-speed motor, such 
as shown in Fig. GO, offers a welcome solution. Such 
machines are compact and more readily controlled, but are 
necessarily rather more expensive. A silent chain drive may 
connect the motor with the driving shaft, so that electric 
control and double gearing together give the necessary speed 
changes. 

In Fig. 60 a slow-speed motor connects directly with the 
shaft, taking the place of the usual cone pulley without 
modifying the general design of the machine in the 
least. 

78. Power and Capacity. 

The boring mill, from the nature of its work and the con¬ 
ditions which brought it into existence, is a heavy-weight 
machine and a large consumer of power. Such machines as 
have been illustrated in this chapter weigh from 5000 to 
75,000 pounds, according to size, the former figure correspond¬ 
ing to the 30-inch and the latter to the heavy 12-foot 
machine. 

The power required in proportion to the amount of metal 
removed per hour is somewhat greater than for a lathe of 
the same swing. Experiments made under the direction of 
the writer at the shops of the Wellman-Seaver-Morgan Co. 
in Cleveland were reported in Cassier’s Magazine for 
December 1903, from which the following results are taken. 
A test on a 37-inch boring mill driven by a direct-connected, 
variable-speed motor of five horse-power developed the results 
given in the following table. 








Fig. 60 . 

GEARED ELECTRIC DRIVE FOR BORING MILL. 










BOEING MILLS 


143 


Work, cast steel gear blank, 22^ inches in diameter and 
5 inches face. 


Cutting Metal. 

Running Idle. 

Controller 

Time. 

Horse- 

Horse- 

Notch. 

Minutes. 

Power. 

Power. 

5 

33 

3-00 

1-36 

6 

52 

3*21 

1-31 

7 

5 

2*16 

1*31 

9 

10 

0-19 

V —i 

1-57 


Total duration of test, ... 1 hour 40 minutes. 

Total weight of metal removed, . 31 pounds. 

Metal removed per net H.P. per hour, 17*8 pounds. 

Net H.P. per pound of metal per hour, 0*056. 

Similar tests on five different machines, ranging in size 
from 3 to 10 ft. swing, showed a consumption of power 
when running empty of from one to two horse-power, and an 
average net horse-power consumed in cutting metal of *091 
per pound of metal per hour. Two lathes of 4 ft. and 5 ft. 
swing in the same shop required from one to two horse¬ 
power empty, but only consumed from *045 to *0 7 horse-power 
per pound of metal per hour, the first figure being for cast 
iron and the latter for cast steel. The motors used on the 
lathes were of the same character and size as those used on 
the 5 ft. and 8 ft. mills respectively. 

The table below shows common practice in the matter of 
motor power for boring mills, the motor in each case being 
supposed to be amply large for any probable over-load on the 

machine. 

g w j n g Horse-Power of Motor. 

10 feet 19 to 15 

7*5 to 10 
7*5 to 10 
5 to 7"5 
5 to 7*5 
5 


8 

7 

6 

5 


55 


5 5 


55 


4 

3 


55 


55 


5 






















144 MODERN AMERICAN MACHINE TOOLS 


The variations in power for the same size of machine are 
due to a difference in the character of the work and in the 
material to be cut. 

Although the power required in proportion to material 
removed is probably greater than for an engine lathe of the 
same capacity, the greater convenience of the boring mill, and 
the rapidity with which work can be handled and machined, 
are advantages which outweigh all other considerations. 
When worked to its limit, the boring mill can undoubtedly 
remove more metal per hour than a face-plate lathe of the 
same swing. 

79. Mills with Movable Housings. 

When most of the work handled in a shop is of a certain 
standard size, and there are only occasional pieces of a larger 
diameter, it is convenient to have a machine which can be 
temporarily extended for the larger work. This general ques¬ 
tion has already been discussed under the head of gap lathes 
and widened planers, and nothing further need be said here. 

In a machine of this class the housings are arranged to 
slide on grooved ways to and from the table, and can be firmly 
bolted in the desired position. 

In all large machines it is necessary that this adjustment 
should be effected by power. To allow of boring when the 
housings are drawn back, an extension head is attached to 
the cross-rail. 

In some machines this extension takes the shape of an 
auxiliary cross-rail at right angles to the main rail, and fitted 
with a saddle and tool head of its own. This construction 
permits of the use of the auxiliary for boring, turning, and 
facing the casting on the hub while the other heads are 
working at the larger diameters. 

80. Horizontal Boring Machines. 

As the boring mills just considered take the place of the 
lathe with the work bolted to the face-plate, so the hori- 


BOEING MILLS 


145 


zontal boring machine lias been designed as a substitute for 
the lathe with the work bolted to the carriage. In finishing 
either plane or cylindrical surfaces, there constantly arises 
the question as to whether the work or the tool should move 
for the cut, and as to whether the work or the tool should 
traverse for the feed. Planer versus shaper is one example 
of this, and boring in the chuck versus boring on the carriage 
another. 

The proper method depends upon the shape and size of 
the piece, and the shape and surface of the cut. An intelli¬ 
gent workman would mount cylindrical pieces of large 
diameter and slight overhang upon the face-plate of his lathe, 
especially if the surface to be finished had the same character¬ 
istics. On the other hand, if the part to be machined was 
irregular in shape and the finish consisted of holes of small 
diameter and considerable depth, he would bolt the work to 
the carriage and use a boring bar. 

Precisely the same considerations would determine his 
choice of vertical mill or horizontal machine. In other words, 
it is primarily a question of holding the cutting tool. 
Wheels, pulleys, rings, and short cylinders are best handled 
on the vertical boring mill. Frames, headstocks, brackets, 
and long cylinders naturally find a place on the horizontal 
machine. The latter machine has been evolved from the 
engine lathe by a gradual process of selection and growth. 
The carriage of the lathe was never well adapted for carrying 
work, since it had no vertical or horizontal adjustment, and to 
get the work in line required a tedious process of blocking. 

Furthermore, the spindle of the lathe had no traverse for 
feeding the boring bar or reamer, and it was necessary to 
move the work against the tool at a sacrifice of power and 
convenience. 

We may then briefly define a horizontal boring 
machine as a lathe in which the spindle has a longitudinal 
traverse, and the carriage has one or more adjustments for 
setting the work. 

K 





146 MODERN AMERICAN MACHINE TOOLS 


As a study of the following pages will show, there is 
considerable similarity between the various types of machine, 
the principal difference being in the method of adjustment of 
the table to the spindle, and vice versa. 

Perhaps the best way to classify the different machines 
would be as follows : (l) Machines with stationary heads and 
universally adjustable tables. (2) Machines with adjustable 
heads. (3) Duplex or multiple spindle machines. (4) Special 
machines for a limited range of work. 

8i. Machines with Stationary Heads. 

This, the usual type of machine, is that illustrated in Fig. 
61, which shows the ordinary characteristics of the type. An 
analysis reveals the following elements, which may be discussed 
separately :— 

(a) The frame and housings or uprights. 

(b) The head and its boring spindle. 

(c) The table and its supports. 

(cl) The feed and speed control. 


82. The Frame. 

The frame of the usual type of boring machine consists of 
a flat bed-plate resting on the floor as on a foundation and 
having a flat top planed true and furnished with T-slots. In 
extreme cases it would be possible to remove the table and 
mount the work directly upon the bed-plate. 

On one end of this bed is bolted the cabinet for the head- 
stock. On the other end is clamped the adjustable housing 
or yoke which forms a characteristic feature of this type of 
machine. The primary use of the yoke is to hold a bushing 
for the outer end of the boring bar; but aside from this it 
serves to steady the outer end of the table, the slides of the 
yoke being slotted to receive clamping screws. The yoke can 
be adjusted to and from the head for different lengths of bar, 











HORIZONTAL BORING AND DRILLING MACHINE. 




















148 MODERN AMERICAN MACHINE TOOLS 


and on the larger machine screws and crank are provided for 
moving it. The cabinet is usually in one casting with the 
headstock, and has on the left side a long bracket to support 
the mechanism for feeding the spindle. 

The general design of machines of this class shown in 
Fig. 61 is pleasing to the eye and in accordance with modern 
ideas on this subject. The machines are well balanced and 
free from useless curves and ornamentation. 

83. The Boring Head. 

The stationary headstock of machines such as that in 
Fig. 61 differs little from that of an engine lathe save in the 
provision made for longitudinal motion of the spindle. The 
last-named piece is of steel and has both a rotary and a 
sliding motion. Outside it is another spindle, usually of cast 
iron, which has only the rotary motion in the spindle bearings 
and which turns the steel spindle by means of a key or feather. 
The feed or traverse of the inner spindle is effected by a 
sleeve between two collars seen in the cuts at the left of the 
headstock. This sleeve slides to and fro on the long bracket 
and is controlled by a rack and pinion mechanism. 

The machine illustrated has the usual arrangement of 
cone pulley and back gears. There are five steps on the cone 
and double back gears, giving fifteen spindle speeds in all. 
Some machines have a triple-geared drive, the cone pulley 
being on a separate shaft, an arrangement which has already 
been noticed in some turret lathes. 

The advantages of this combination are the absence of any 
belt pull on the spindle bearings and the possibility of taking 
off the cone belt at any angle. 

By means of a lever near the main driving gear the 
machine can be stopped or can be started with either a fast or 
a slow motion. The boring bar itself is provided with the 
usual slots for the insertion of cutters and with a taper hole 
in the end for the accommodation of drills and reamers. 


BORING MILLS 


149 


A face plate on the outer revolving spindle may be 
arranged to carry a facing head with automatic feed as shown 
in Fig. Gl. 

It will be noticed that in the spindle arrangement of the 
machine just described the steel spindle is not subject to any 
journal wear since it has only a sliding motion in the outer 
spindle. The journal bearing comes on the outer spindle 
alone which revolves in the usual head boxes. 


84. The Table. 

The table is somewhat similar in character to that of a 
milling machine, a sliding bracket supported by screws. It is 
gibbed to vertical ways on the head cabinet and is raised and 
lowered by vertical screws. The smaller machines have one 
and the larger two of these screws. They turn by power, 
usually by means of worm wheels engaging with endless 
screws on a horizontal shaft. 

This shaft, as may be seen in the cut, is driven by a 
pulley and disengaging clutch at the left of the machine. The 
table may be clamped at either end when in position. A 
saddle capable of being moved lengthwise of the table and 
fastened in any desired position carries in turn the carriage 
itself The latter can be adjusted cross-wise of the table and 
is provided with the usual T-slots for fastening the work. It 
is thus possible to clamp work rigidly to the carriage without 
the use of blocking, and then by a combination of the vertical 
and two horizontal adjustments to bring the work into the 
desired relation to the boring spindle. 


85. Speed and Feed Mechanism. 

The speed changes have already been alluded to, being 
similar in character to those of an engine lathe. There are 
from eight to fifteen different speeds, depending upon the size 
of the machine. 



150 MODERN AMERICAN MACHINE TOOLS 


The feed mechanism is confined entirely to the longi¬ 
tudinal movement of the spindle as the adjustments of the 
table are controlled by hand. 

In both machines illustrated there is a quick feed operated 
by the hand-wheel in front of the headstock. Six or more 
automatic feeds are furnished and provision is made for 
reversing the feed without reversing the machine itself. The 
motion of the spindle is effected by a rack attached to the 
sliding sleeve before mentioned. 

On some special machines a power cross-feed is provided 
for the carriage, and also a rotary table with circular feed. 
These attachments make it possible to use the machine for 
straight and circular milling, and really have nothing to do 
with the boring functions of the machine. 

86. Capacity and Weight. 

The class of machines just described have tables not to 
exceed 10 feet in length and at a maximum distance from the 
spindle of not more than 3 feet. The usual range and weight 
may be determined from the following table :— 


Length of 
Table. 
Feet. 

Centre to 
Carriage. 
Inches. 

Feed of 
Spindle. 
Inches. 

Carriage 
Cross Feed. 
Inches. 

Net 

Weight. 

Pounds. 

4 

20 

18 

16 

6,000 

6 

25 

30 

24 

10,000 

8 

30 

36 

30 

16,000 

10 

35 

36 

30 

30,000 


87. Machines with Sliding Head. 

There are certain disadvantages in making the table of a 
boring machine adjustable vertically which have led to the 
adoption of a different type by some builders. The raising 
and lowering of the table is attended with some difficulty 






















HORIZONTAL BORING MACHINE. 





















152 


MODERN AMERICAN MACHINE TOOLS 


when the work is unusually large or heavy, and the necessary 
length of table in the larger machines renders it difficult to 
secure the proper firmness and rigidity. 

In Fig. 62 is shown a machine with the vertical adjust¬ 
ment in the head itself. The weight of the head and its 
attachments being practically constant, it is possible to so 
counterbalance them as to make adjustment easy. 

The bed in this case takes the form of a box girder 
similar to a lathe bed, and the carriage or saddle rides directly 
upon this. The yoke for the outer end of bar is fastened to 
the same ways. * The advantages of this arrangement for 
some kinds of work are well shown in the illustration, where 
the heavy bed of another machine is shown mounted and 
ready for boring and facing. The impracticability of doing a 
job of this size on the ordinary machine is evident. 

The machine shown is provided with milling feeds for 
both spindle and platen, so that facing of plane surfaces may 
be done without resetting the work. When the head is used 
for boring, the head itself and the bushing in the yoke which 
supports the outer end of bar are raised or lowered simul¬ 
taneously by means of a connecting shaft. As is clearly 
shown in the figure, the head slides on a vertical housing, 
being counterbalanced by a chain and weight, and can be 
clamped in any desired position. The necessity for a vertical 
adjustment of the head complicates the driving mechanism 
somewhat. 

The power is transmitted from the driving cone by means 
of bevel gears and vertical shafts and is thus available for the 
rotating of the spindle, the feed of the boring bar, the eleva¬ 
tion of the head, and the longitudinal and transverse feeds of 
the carriage. Lhe face plate on the end of the revolving 
spindle is driven by a pinion and annular gear. Facing 
attachments may be bolted directly to this plate and thus be 
used independently of the boring bar. 

The makers call this a precision machine from the fact 
that all adjusting parts are cut with special care, and that 


BORING MILLS 


153 


the use of micrometers permits the machine to be set 
accurately without the use of jigs. 

88 . Large Machines. 

As the size of machine increases the weight of table and 
work forbids any attempt at adjustment there, and all the 
vertical and horizontal motions are given to the head of the 
machine. Fig. 63 gives a good idea of this type, and repre¬ 
sents a machine having a vertical adjustment of 4 feet and 
a horizontal travel of 8 feet, with a 3-foot traverse to 
the boring spindle. The bed of such a machine consists of 
two parts, the large stationary floor plate and the parallel 
ways for the travel of the column. The ways are usually flat, 
and the foot of the column has gibbed slides of large area. 
The extension shown in the cut forms a platform for the 
operator. 

As may be seen in the figure, the driving mechanism is all 
located at one end of the ways, there being the usual cone 
pulley and back gears for the main drive, and in addition 
gearing for moving the column on the ways and for hoisting 
the saddle on the column. 

As it is especially desirable on such large machines that 
the work should be finished with as little resetting as 
possible, feeds suitable for milling and facing are given to 
both column and saddle. After once setting the work on the 
table it is then possible to bore all parallel holes and to face 
all flat surfaces within reach. 

The saddle is counter weighted and moves on broad, flat 
ways. The face-plate on the spindle has teeth cut on its 
edge and is directly driven by a cut pinion. 

Quick traverses as well as power feeds are provided for 
all the adjustments, and the controlling levers and handles are 
all within easy reach of the operator’s platform. From this 
one position he can control the speed of boring, can raise or 
lower the saddle, or can move the column either way. Some 





HORIZONTAL BORING, DRILLING, AND MILLING MACHINE. 
























BORING MILLS 


155 


machines are provided with tapping attachments by which 
holes may be drilled and tapped without resetting the 
machine. 

In finishing beds and frames of unusual weight and size, 
it is practicable to move a machine of this character to the 
work and perform all necessary operations without disturbing 
the piece operated on. 

If an outboard bearing is needed for the boring bar, a 
column is bolted to the floor plate for this purpose. 


89. Tilting Table. 

Fig. 64 illustrates a so-called universal machine for drill¬ 
ing and boring holes at any angle. The bed and column of 
this machine are similar to those just described, but in place 
of the usual floor plate is substituted an adjustable table. 

This table 1 las a horizontal motion to and from the column, 
a rotating motion on a vertical axis, and a tipping motion 
from 0 to 90 degrees. To quote the language of the makers, 
‘ it is possible on this machine to drill and face holes on five 
sides of a cube without re-chucking.’ 

The adjustments of the table are made by means of worms 
and gears operated by hand cranks, as they are not intended 
for feed motions. The head of the machine has the feeds 
usual in machines of this class. The advantages of this type 
of table are too apparent to need discussion. The machine as 
shown is driven by an electric motor with geared speed 
control. 


90. Cylinder-Boring Machines. 

Among special machines may be numbered those intended 
for boring the cylinders of pumps and engines. The 
cylinders of the duplex pump frequently being in one casting 
are best finished on a two-spindle machine, which will bore 
both cylinders at once. This machine is fashioned on the 
engine lathe plan with a stationary head and an adjustable 





40-INCH MACHINE, WITH UNIVERSAL TABLE MOTOR-DRIVEN. 

Detrich and Harvey Machine Co., Baltimore, Ohio. 







BORING MILLS 


157 


carriage travelling on ways. The two spindles are precisely 
alike, and the outer ends of the boring bars are supported 
by a double yoke fastened either to the carriage or to 
the bed. 

Fig. 65 illustrates a characteristic design for this type of 
machine. The great strength and rigidity of construction 
are manifest from the illustration and show the capabilities 
of the machine for heavy and continuous work. 

The extensive use of the Corliss type of engine with its 
cylindrical valves at right angles to the cylinder proper, has 
led to the design by the Niles Tool Co. of a machine especially 
adapted for boring cylinders and valve ports simultaneously. 
As would be expected in a machine for such heavy work, 
massiveness is the prevailing characteristic. The boring bar 
has itself a hand traverse for setting, but the feed tor cutting 
is accomplished by sliding the boring head along the bar, a 
feed screw being used for this purpose. The economy of 
room by this modification is apparent. The bar is of large 
diameter and supported at each end by long bearings. 1 he 
feed of the cutter head is regulated by change gears at the 
head end. There are two facing heads clamped to sleeves 
which revolve with the bar, and which can be swung down 
out of the way when not in use. 

The peculiarity of this machine, however, is in the two 
auxiliary columns which carry the bars for boring the ports. 
These really constitute an independent boring machine at 
right angles to the main machine and equipped with two 
adjustable heads. These heads have the usual boring and 
facing attachments, and are driven independently ol the main 
machine by a cone pulley. 

It is thus possible to conduct the port-boring without 
reference to the other work, since the setting of the cylinder 
is undisturbed. 

Such a machine is not adapted nor intended foi miscel¬ 
laneous work, but finds an ever-widening field as the manu¬ 
facture of large Corliss units increases. 









Fig. 65. 

TWO-SPINDLE HORIZONTAL BORING MACHINE. 














BOEING MILLS 


159 


91. Miscellaneous Machines. 

There are numerous varieties of boring: and drilling: 
machines which it is impossible to do more than mention here. 
A.s has been noticed, the boring machine comes very close to 
the milling machine in some of its adaptations. In fact, 
many such machines are milling machines, and will be dis¬ 
cussed under that head. 

Other types are used as rotary planers, so-called, if we 
may be willing to admit any distinction between the rotary 
planer and the milling machine. Tapping and thread-cutting 
attachments are frequently introduced, but in no way change 
the principle of the machine. 

Multiple spindle machines for drilling and tapping belong 
rather to the class of drill presses, and will be treated under 
that division. 

Special machines have been designed for boring engine 
frames and cylinders and for finishing generator and motor 
frames, while others have been built solely for use on 
structural work. 

The larger machines of the horizontal class are good sub¬ 
jects for independent motor drives, and most of the machines 
just described are adapted for electric transmission. 

The motor is usually of the constant high-speed type con¬ 
nected directly by gearing to the main spindle. The enor¬ 
mous size of some of these machines and the extent ol floor 
space covered make electrical control particularly economical 
of time. 









CHAPTER VI 


DRILLING MACHINERY 

92. The Upright Drill. 

Convenience in handling and clamping the work, and 
facility for seeing what is being accomplished, have brought 
about the almost exclusive use of the upright machine for 
ordinary drilling. It may be found of almost any size and 
weight, from the so-called sensitive drill of Fig. 66 to the 
massive drill press of Fig. 70. 

The ordinary drill press of the machine shop, having a 
capacity of from 24 to 36 inches, is in almost universal use, 
and next to the engine lathe may be regarded as the most 
necessary tool in the shop. 

The elements of any upright machine are— 

(a) The column. 

( b ) The drilling head and spindle. 

(c) The table. 

(d) The feed mechanism. 

93. The Column. 

The necessary height of this class of machine and con¬ 
siderations of stability have led to the general adoption of 
a hollow circular column with a broad base. In the sensitive 
drill, Fig. 66, the base is circular and merely serves as a 
support, while in the larger machines, as shown in Figs. 67 
and 68, it is utilised as a floor plate for clamping large work. 

1G0 





161 


DRILLING MACHINERY 







In any type ol machine, the circular section lends itself 
readily to the swinging of the table horizontally. Even in 
machines whose size has 
warranted the adoption 
of a massive rectangu¬ 
lar housing, as in Fig. 

70, the table is still 
swung from a supple¬ 
mentary round column. 

The function of the 
column is threefold : to 
support the swinging 
table ; to carry the tool 
head and spindle; to 
afford a support for the 
shafting. 

It is in the adapta¬ 
tion of the column to 
this threefold use that 
the fancy of the designer 
has run riot. The tree 
form has evidently been 
the basis of design, as is 
natural, and we find all 
varieties of tree in evi¬ 
dence, from the grace¬ 
ful elm and the sturdy 
oak to the tropica' 
banyan. 


For the support of p IG# 6 6. 

the table, the column sensitive drill. 

offers a smooth cylmdll- The Dwight Slate Machine Co., Hartford, Conn. 

cal surface, permitting 

the two motions of horizontal swinging and vertical ad- 
j ustment. 

As regards the tool head, it may be noted that the 
















162 MODERN AMERICAN MACHINE TOOLS 


column is subjected to a bending moment due to the upward 
pressure on the spindle, and that in ordinary drilling this is 
more severe than the twisting moment. 

This bending moment will be uniform from bottom to top 
of column, and will then diminish uniformly as the column 
approaches the spindle. This indicates a column of uniform 
diameter and a goose-neck of diminishing diameter—see Fig. 
67. If the top of the column is reinforced by the braces which 
support the shaft, its diameter may be correspondingly 
lessened. The secondary column in the rear, Fig. 68, helps 
to reduce the bending moment on the main column. A 
hollow column, exposed to a transverse moment, may be rein¬ 
forced internally by flattening the core on two sides, making 
the section of an o shape. 

Sensitive drills and machines having a capacity of 20 
inches or less are usually built with but one column, and 
the shafting is supported by brackets at top and bottom as 
in Figs. 66 and 67. 

In the larger sizes where double gearing is introduced at 
the top, most makers prefer to put in a secondary column to 
support upper and lower shafts and to brace the main column 
—see Fig. 68. 

the design shown in the last-mentioned illustration is 
correct in principle and pleasing to the eye. In this machine, 
the secondary column is parallel to the first and is straight, 
as it should be, while the whole forms a well-balanced and 
symmetrical structure. Fig. 69, on the other hand, shows the 
application of the single column to a large and heavy machine, 
the makers depending on diameter and thickness of metal for 
the necessary rigidity. It is apparent from the cut that this 
machine will be stiff and strong, but there is not as good 
economy of metal as in Fig. 68. 

1 he design is undeniably homely, there being too many off¬ 
shoots from the parent stem to be pleasing to the eye. The 
absence of the lower countershaft and its brackets" and ap¬ 
pendages does, howe\ er, make the machine more compact and 




DRILLING MACHINERY 


163 


more convenient to get at. It is possible for the operator to 
walk entirely round this machine without danger or difficulty. 



Fig. 67. 

20-INCH DRILL PRESS. 

American Tool Works Co., Cincinnati, Ohio. 


For heavy and rapid cutting, the style of column shown 
in Fig. 70 possesses greater rigidity than any of these just 










164 MODERN AMERICAN MACHINE TOOLS 


mentioned, being of tlie hollow box form and offering great 
resistance to bending. The table may be supported as shown, 
or the round column may be omitted and a table and bracket 
of the milling machine type be jibbed directly to the face of 
the cabinet. 


94. The Head and Spindle. 

The spindle, like that of the horizontal machine, must 
have the two motions of rotation and of longitudinal traverse. 

It consists of a vertical steel shaft passing through two 
sleeves which give it the two motions mentioned. The upper 
sleeve is driven by a gear or pulley and imparts rotation to 
the spindle through a key; the lower slides vertically, carry¬ 
ing the spindle up and down by means of hardened steel 
collars. These collars are frequently provided with ball or 
roller thrust-bearings. 

The motion of the spindle in the upper sleeve is sliding 
only, and the latter revolves in a bushing at the extremity of 
the goose-neck. The lower sleeve slides vertically without 
rotation in the head of the machine, being fed up or down by 
a rack and pinion. 

It is in the attachment of the lower head to the column 
that we find the greatest variation among different machines. 
Machines, like those shown in Figs. 67 and 70, have this head 
cast to the column of the machine, and all the adjustment of 
cutting tool to work must be effected by the traverse of the 
spindle or the raising and lowering of the table. While this 
construction simplifies the feed mechanism and gives great 
rigidity to the head, it limits somewhat the adaptability of 
the machine. 

For a wider range of work and greater convenience, the 
sliding head, as seen in Fig. 68, is preferred. Most manu¬ 
facturers can supply either style, as desired. The sliding head 
is gibbed to ways on the front of the column, and can be 
adjusted up or down according to the height of the work, so 



J. E. Snyder, Worcester, Mass, 


Fig. 68. 

28-INCH UPRIGHT DRILL 























166 MODERN AMERICAN MACHINE TOOLS 

as to support the spindle near the cutting tool. "With a 
machine like that shown in Fig. 67, it is frequently the case 
that the spindle has considerable overhang, and does not 
afford firm support to the drill. This is especially true when 
drilling work on the floor plate. 

In some machines the head is adjusted by hand, and is 
then clamped to the column, the feed being efiected in the 
usual way by rack and pinion. 

Fig. 68 shows a machine in which the sliding head itself 
moves up and down with the feed. The head has an extra 
long bearing on the column, and is driven by a pinion engaging 
with a stationary rack not seen in the figure. 

This design does away entirely with the rack and pinion 
on the sleeve, and gives a much longer traverse than is 
practicable with the ordinary feed motion. 

The 28-inch machine, shown in the figure, has a feed of 
25 inches, which makes it particularly desirable for boring 
longf holes or two holes which come in line. 

A lever for quick return is provided, which makes it pos¬ 
sible to raise or lower the head rapidly by hand. The head is 
counterbalanced by a weight inside the column. 

The reverse of the usual arrangement is seen in Fig. 69, 
where the driving gear is at the lower end of spindle and the 
feed mechanism at the top. The advantage of this arrange¬ 
ment for heavy work is manifest, since the spindle is no longer 
subject to a twisting moment throughout its length and is less 
likely to spring and chatter. 

The counterbalancing of the spindle should also be 
noticed. 

95. The Table. 

The table of the upright drill may be round or square, and 
may or may not swing in a horizontal plane, but it always has 
some vertical adjustment. Its most usual form may be seen in 
Fig. 67, a horizontal circular plate, capable of turning 011 its 
own axis and of being swung with its supporting bracket 


ft 



Fig. 69. 

GO-INCH VERTICAL DRILLING MACHINE. 


Niles-Bement-Pond Co., New York 









168 MODERN AMERICAN MACHINE TOOLS 

about the circular column. It may be raised or lowered with 
the bracket, and may be rigidly clamped as to all three 
motions. 

The raising or lowering of the brackets on the post is 
usually effected by a rack and pinion, as in fig. 68, but fig. 
67 shows the use of a screw for this purpose, this latter 
method has the advantage of being more powerful and of 
bringing the elevating crank at a constant and convenient 
height for the operator. 

In the sensitive drill, Fig. 66, the table lias only the 
swinging motion, and a supplementary table is provided below 
for long work. This latter can be adjusted vertically on a 
dove-tailed slide cast to the column. Fig. 68 illustrates a 
square table fitted with a chuck for special drilling and boring. 
Machines of this latter class are sometimes equipped with a 
revolving table driven by power. This facilitates truing up 
the work and makes a substitute for the chucking lathe. 

Some drills are equipped with a compound table similar 
to that of a milling machine, but operated by hand. All 
such devices tend to bring the drill into the milling machine 
class, much as has been noticed with the horizontal 
machines. 

Fig. 69 shows a rectangular table with a horizontal adjust¬ 
ment to and from the column on parallel ways. 

The machine illustrated in Fhn 70 has a bracket of unusual 
rigidity underneath the table, as befits a tool intended for 
heavy work. 

Nearly all the machines illustrated have a lower table or 
floor plate, which is finished to a plane surface and pro¬ 
vided with T-slots for the accommodation of large work. 


96. The Gearing and Feed Mechanism. 

The driving mechanism of the upright drill consists of a 
countershaft at the bottom provided with tight and loose 
pulleys and a stepped cone. The pulleys are usually so 


169 




DRILLING MACHINERY 

arranged as to necessitate a quarter-turn belt from the line 
shaft, unless the machine is set parallel to the latter. The 
machine illustrated in Fig. 68 has its tight and loose 
pulleys at right angles to the countershaft, thus obviating 
the difficulty just mentioned. A somewhat similar arrange¬ 
ment may be seen in Fig. 70. 

the upper shaft of the machine carries the second cone 
and the necessary double gearing for speed changes. This 
shaft usually drives the spindle through bevel gears. Most 
machines of this class have four steps on the cones, making, 
with the double gearing, eight changes of speed. The 
various illustrations show the manner of gearing quite 
clearly. Triple gearing is introduced on some of the larger 
machines. 

There is considerable variety in the mechanism for feed¬ 
ing the spindle, depending on the style of frame and head 
adopted. 

As has already been noticed, the vertical motion of the 
spindle is usually controlled by a rack and pinion. This 
pinion is turned by a hand-wheel for quick traverse, and by a 
worm and wheel which are engaged for the power feed. A lever 
feed is sometimes introduced at this point, as shown in Fig. 67. 

The various speeds of the feed mechanism are obtained by 
stepped cones, which are located sometimes on the spindle 
itself, as in Fig. 67, and sometimes on the upper shaft, as in 
Figs. 68 and 69. 

The use of the sliding head necessitates the splined 
vertical shaft for transmitting motion from the driving shaft 
above to the feed mechanism on the head. This arrangement 
is apparent in Fig. 68, as is also the automatic stop rod for 
(controlling the depth of hole drilled. 

The power feed can be disengaged by a clutch near the 
hand-wheel and the spindle fed slowly or rapidly by hand. 
Thus, the machine shown in Fig. 70 has a power feed, a hand- 
worm feed, a hand-lever feed, an automatic stop, and a quick 
return. Usually, three changes of feed are provided, but on 







Balcer Bros., Toledo, Ohio. 


Fig. 70. 

HEAVY DRILL PRESS. 



















DRILLING MACHINERY 171 

some of the larger machines a geared feed is used, so that the 
machine may he employed for tapping. 


97 - Radial Drills. 

In the ordinary upright drills which have just been con- 



Fig. 71. 

PLAIN RADIAL DRILL. 

The American 'Tool IVorlcs Co., Cincinnati, Ohio. 

sidered, the vertical axis of the spindle is stationary, and any 
side adjustment must be obtained by moving the work. As 
the size and weight of the work increases, we are confronted 
again by the old problem of whether it is cheaper to move the 
work to the tool or the tool to the work. 

The radial drill is a concession to the latter principle, and 






















172 


MODERN AMERICAN MACHINE TOOLS 


makes it possible to drill holes in a large casting or forging 
at almost any location or angle without moving it from its 
position. 

Radial drilling machines have various degrees of freedom, 
and must be distinguished accordingly as plain, half-universal, 
or universal. 

In the plain machines, neither arm nor head has any 
swivelling motion, and only vertical holes can be drilled. 
The half-universal machines have a swivelling head only, 
while the universal drills have both arm and head arranged 
to swivel, so that holes may be drilled at an angle. For the 
ordinary run of work the plain machine is the better adapted, 
as being simpler and more easy to operate. 

The elements of the various machines are, however, much 
the same, and will be considered separately. They con¬ 
sist of— 

(a) The column and its base. 

(b) The radial arm. 

( c ) The tool head. 

(d) The driving mechanism. 

(e) The feed mechanism. 

98. The Column and Base. 

The base of the radial machine is much like that of its 
predecessor, the drill press—a massive floor plate with its 
upper surface planed and slotted for the accommodation of 
the work. To this base are bolted the column itself and the 
stand for the countershaft. Unlike its neighbour of the 
ordinary drill press, the column of the radial must stand 
alone, and instead of carrying the sliding head, must serve as 
a centre of motion for the radial arm. 

There are, however, several types of column in common 
use which differ from each other in form and in principle. 
The favourite type is the double circular column, as 
illustrated in Figs. 71 and 72, and shown in detail in Fig. 73. 




DRILLING MACHINERY 


173 


The outer sleeve is finished on the outside to fit the hub 
of the arm, so that the latter may slide freely from top to 
)bottom. When the arm is adjusted at the proper height, it 
jis clamped to the sleeve and the two then turn as one piece. 



Fig. 72. 

HALF-UNIVERSAL RADIAL DRILL. 


j Bickford Drill and Tool Co., Cincinnati, Ohio. 

As may be seen by reference to Fig. 73, the sleeve has bear¬ 
ings at top and bottom on the inner column, the latter being 
in one casting extending from the base to the top of the 
machine. The sleeve rests at the bottom on a thrust bearing 
I of conical rollers, which give it great ease of movement. 





































174 


MODERN AMERICAN MACHINE TOOLS 

When in the desired position, it is clamped by means of the 1 
V-shaped ring at the bottom. As is shown more clearly lr I 1 
Figs. 71 and 72, this ring is split on one side and fitted with 
a clamping bolt and lever. 

Finally, when both arm and sleeve are clamped in the 

desired position, the whole forms ! * 
practically a single member fre 
from joints and back-lash. 

The sleeve and inner column | : 
together constitute a double hollow 1 
cylinder of the best section to resist 
the stresses due to bending and 
torsion. 

The second type of column differs 
radically from the one just described, 
as may be seen by reference to Fig. 
74. It consists of a post of a para¬ 
bolic outline and of a box section I 
having on the front flat ways for a 
sliding head, and carrying at the 
top a countershaft similar to that 
on an ordinary upright drill. In 
fact, the design differs from that of 
the sliding head drill only by the 
interposition of a radial arm be¬ 
tween the saddle and the tool head. 
The saddle is gibbed to the rect¬ 
angular ways and carries vertical 
bearings for the trunnions of the arm. The swinging motion j 
is brought entirely away from the column, and provision is 
made on the latter for vertical movement alone. 

While the arrangement just described may offer some 
advantages on the score of the convenience of manipulation, 
it does not seem to be so logical a design as that where the 
circular column is employed. 

For a horizontal pressure, such as that exerted by the 



Fig. 73. 

Column—Bickford Drill. 













































































DHI LLING M A CHINEEY 17 5 

cutting tool of a planing machine, the parabolic upright is 
correct. 

In any form of vertical drilling machine, the principal 
pressure is that due to the point of the drill and is directly 
upwards. The resultant bending moment on the column will 
be the same from the bottom to the location of the radial 
inn, will he independent of the position of the arm on the 
column, and will depend only on the distance of the drilling 
axis from that of the column. The straight column is, there¬ 
fore, correct for this class of machine. The rigidity of the 
combination, when drilling is being done at a large radius, 
is dependent upon the length of the vertical bearing of the 
arm on the column ; and here also, the first-described design 
has the advantage, since the whole length of the column is 
available for this purpose. Lastly, the circular post allows 
the arm to swing completely around the machine, a freedom 
which is sometimes very convenient. 

There are various modifications of the types just con¬ 
sidered, one of which is shown in Fig. 75. This machine has 
a cylindrical column with the outer sleeve revolving on a 
roller bearing, but the radial arm slides vertically on rect¬ 
angular ways, so that the design is a sort of compromise 
between the two types already considered. 


99. The Radial Arm. 


The arm, which constitutes the distinguishing feature of 
the radial machine, and gives its name, may have one, two, or 
three motions ; the swinging about the column ; a combination 


of this motion with vertical adjustment, as in plain radials ; 
the addition of a swivelling motion on the column, as in 

universal machines. (See Fig. * 6.) 

Its shape is modified by the above-named conditions and 
by the type of column adopted. In general, it is ot a tubular 
section reinforced by parabolic webs to take the bending 
moment. The stress due to this moment is the most severe 









176 MODERN AMERICAN MACHINE TOOLS 


to which the arm is subjected, but there is also some torsion 
due to the spindle being at one side of the arm. The tubular 




i 





Fig. 74. 

3-FOOT ARM RADIAL DRILL. 

Fosdick Machine Tool Co., Cincinnati, Ohio. 


section is well adapted to withstand stress due to the latter 
cause. 

Flat ways are cast to the face of the arm for the spindle 

























DRILLING MACHINERY 


177 


head. bigs. / 1 and 75 show a good design with the parabolic 
web above in the best position to withstand the bending 
action. This arrangement also leaves a clear space under¬ 
neath and permits table and head to he brought close to 
column. Some radials have a design of a different character, 
the arm being kept straight on top to accommodate the gear¬ 
ing and a web added underneath. Neither on the score of 
strength nor of convenience is this arrangement as good as 
the other. The arms shown in Figs. 72 and 74 have the 
web above and below, a style which is symmetrical, but not 
so correct as that first mentioned. 

When a circular column is employed, the arm has a split 
hub embracing the rotary sleeve and clamped to it by bolts 
with hand-lever nuts. 

When the rectangular column is used, the arm has trun¬ 
nions which turn in split bushings on a sliding saddle, and 
the bushings are clamped on the trunnions to secure the arm 
in position. Ball-bearings on the lower trunnion take the 
vertical thrust. The saddle slides on the rectangular ways of 
the column, and is clamped by gibs and screws in the usual 
manner. 

Owing to the absence of any column bearing at the 
bottom, it is usually possible to bring the arm lower on the 
machine when the saddle is employed than when the arm 
embraces the column. Otherwise, the circular column type 
has the advantage in simplicity and rigidity. The raising 
and lowering of the entire arm and its attachments is effected 
by an elevating screw driven by power from the top of the 
column. 

In the universal radial, Fig. 76 , the arm is attached to the 
hub on the column by a swivelling joint. This permits the 
arm to be revolved on its axis by means of the worm and 
wheel shown, so as to drill holes at any angle in this plane of 
rotation. It is necessary in a universal machine to have the 
column revolve, to avoid too much complication in the saddle, 
but the type shown in Fig. 75 is sometimes adopted. In 

M 






178 MODERN AMERICAN MACHINE TOOLS 


such case, the arm swivels on the face of the saddle. Atten¬ 
tion has already been called to the modifications in the 
attachment of arm shown in Fig. 75. 


ioo. The Tool Head. 

The tool head of the radial drill is practically that of a 
sliding head upright, transferred from the column to the 
radial arm and moving horizontally, instead of vertically. It 
must contain mechanism for revolving the spindle at the 
proper speed, for feeding it automatically towards the work, 
and for stopping and returning it quickly. Some machines 
have also attachments for tapping, while in all drills of the 
universal or half-universal class the head swivels on the arm. 
(See Fig. 72.) The ways on the radial arm are of the 
conventional type, and on these slides a saddle similar to 
those on a planing machine. The bearings for the spindle 
are cast or bolted directly to the saddle in the plain type 
of machine. 

The spindle revolves inside a sleeve, the latter being 
provided with the usual rack and pinion for the vertical feed. 
The swivelling head, sometimes provided, turns on the saddle 
just as in a planing machine and makes the machine a half- 
universal so-called, while in combination with the swivelling 
arm it constitutes the universal mechanism. The traverse of 
the saddle on the arm is usually effected by a rack and pinion, 
although a screw is sometimes employed, as in Fig. 75. 

ioi. The Driving Mechanism. 

The most usual arrangement of shafts and gears for round 
column machines is partly shown in Fig. 73. The horizontal 
shaft drives through bevel-gears a vertical shaft which 
coincides with the axis of the column and operates gearing at 
the top. From these top gears are driven, first, the elevating 






179 


DPd F,LING MACHINERY 


screw ; and second, the mechanism for controlling- the speeds 
and feeds of the spindle. 



36-INCH RADIAL DRILL. 

Dreses Machine Tool Co., Cincinnati, Ohio. 


The gearing for raising and lowering the arm is started, 

stopped and reversed by the vertical rod and lever shown in 

Figs. 71 and 75 at the front side of the column. The dr ivinor 

& 






















180 MODERN AMERICAN MACHINE TOOLS 


mechanism for the spindle is usually at the rear of the column. 
A vertical shaft driven by the top gearing is so splined as to 
drive the gearing on the arm, as the latter moves up and 
down; and as the top gear is concentric with the column, the 
whole arrangement can be turned around the column without 
disturbing the relations. 

O 

The back gears for changing the speed are located in the 
gear case at base of arm, and are so arranged that four 
changes of speed can be obtained by shifting levers on front 
side of case. Four other changes of speed are obtained by 
another gear case with suitable levers situated near the base 
of the column. (See Figs. 71 and 72.) 

In the machine shown by Fig. 71, the back gears are 
located on the spindle head, so that the increased moment 
due to reduced speed is transmitted by the spindle alone. In 
either case, the combination of the two sets gives sixteen 
changes of speed, ranging in geometric progression from 16 
to 267 revolutions per minute for drills of ordinary tool 
steel. 

In machines, such as those shown in the two figures just 
mentioned, the use of an electric motor or of a belt from 
underneath will permit of the revolution of the arm com¬ 
pletely around the column. 

The machine, illustrated in Fig. 75, has a gear case on the 
arm, but the further changes of speed are obtained by means 
of a cone pulley. 

The universal machine, shown in Fig. 76, is driven 
directly from overhead by motor or bevel gearing, but 
the speed changes are obtained by cone pulleys and back 
gearing located at the base of the arm. One advantage 
of this design is the fact that the base of the column is 
kept entirely clear of gearing and shafting, and this makes 
it possible to lower the radial arm close to the bed of the 
machine. 

When the rectangular column is adopted there is neces¬ 
sarily a modification of the driving mechanism. 


DRILLING MACHINERY 


181 


In Fig. 7 4 we see the tight and loose pulleys, the stepped 
cones and the overhead shaft of the ordinary upright drill. 



Fig. 76. 

NILES UNIVERSAL DRILL. 

Niles-Bement-Pond Co., Neiv York. 


The upright shaft is now concentric with the trunnions of 
the arm, and drives both elevating and spindle mechanism 
through trains of gearing. The back or double gearing is 






















182 


MODERN AMERICAN MACHINE TOOLS 

located on the head, and, together with the cone, furnishes 
eight changes of speed. 

The Baush radial drill has a belt drive through to the 
spindle with the double gearing directly on the latter. Ihe 
overhead belting is similar to that of a sensitive drill, and by 
an ingenious device, the power is transmitted to the spindle 
head, as it moves to and fro on the radial arm. This same 
machine is also built with a geared drive similar to the one 
just described. 

Speed cones are especially open to objection on radial 
drills, where changes of size of drill are frequent, and corre¬ 
sponding changes of speed are necessary to the best efficiency. 
The time and trouble incident to shifting a belt often prevent 
its being done. One objection, that may well be urged 
against belt transmission on machine tools, is the fact that 
they are usually out of repair and rarely in a condition to 
give the maximum efficiency. 

102. The Feed Mechanism. 

The mechanism for feeding the spindle vertically is 
naturally located on the head itself. By reference to Fig. 71 
it may be seen that the rack sleeve outside the spindle is 
actuated by a pinion, and this in turn by a worm and wheel. 
A hand-wheel on the pinion shaft gives a quick motion for 
adjustment or return, and another on the worm shaft furnishes 
the regular hand-feed. 

A gear case is conveniently located above the worm shaft, 
and two dials show the different rates of feed. On this 
particular machine eight feeds are provided, ranging in 
geometrical progression from *007 inch to ‘063 inch per 
revolution. A plate on the column shows the different sizes 
of drills used in the machine and the proper feed for each. 
The feed motion is driven by a friction device which will slip 
before anything breaks. 

Most machines are provided with an automatic trip which 


183 


DRILLING MACHINERY 

will stop the drill at any desired depth. Some drills have a 
graduation on the spindle, but the head shown in Fig. 72 is 
fitted with a dial register which can be set to zero when the 
drill enters the work and then the depth read without sub¬ 
traction—a manifest advantage. 

Lhis particular head is also equipped with an automatic 
trip which can be so set as to act at different depths for the 
different holes to he drilled in one position of the work. 

Most of the machines shown are fitted with special tap¬ 
ping mechanism when desired. 

It is hardly worth while to describe the various feed 
mechanisms used by different builders, since they are in the 
main similar to the ones already mentioned, furnishing hand 
and power feeds, fast or slow, and quick return. Some 
machines have a belted feed motion, and in Fig. 76 is shown 
one with gear-shaft horizontal, instead of vertical. 


103. Speeds and Feeds. 

In all types of drilling machinery, whether horizontal or 
upright, stationary or radial, the question of the speed of 
revolution and of longitudinal feed is an important one on 
account of the character of the tools used. The modern twist 
drill is a standard tool for drilling holes in solid metal, and 
numerous experiments have shown approximately the best 
speeds and feeds for combined execution and endurance. 
Equip a machine properly for drilling holes in the solid, and 
there will be ample provision for the reaming and counter¬ 
boring. 

The speeds recommended by the Cleveland Twist Drill Co. 
are a peripheral speed of 30 feet per minute for steel, 35 feet 
per minute for iron, and 60 feet per minute for brass. 

For drilling cast iron, the Bickford Drill Co. recommends 
speeds varying from 35 feet per minute for small drills to 15 
feet per minute for drills over 3 inches in diameter. The 
following table gives the speeds for different sizes of drills 




184 MODERN AMERICAN MACHINE TOOLS 

varying from inch to 81 inches in diameter, as listed by 
that company :— 

1 Cutting Speed. 

Feet per Minute. 

35 

36 
36 
35 
33 
31 
29 
28 
28 
26 
25 
23 
21 
19 
17 
15 


Size of Drill, 
l 


8 

3 


H 

n 

H 

& 

1 7 

1 i 
9 

91 

4 

91 

2 

2f 

3 

3J 


31 

The maker 


Revolutions per Minute. 

267 
222 
184 
153 
128 
106 
88 
73 
61 
51 
42 
35 
29 
24 
20 
17 


*s and users of* twist drills seem to be pretty 
well agreed on the question of speeds, but on that of feeds 
there is a marked difference of opinion. 

The feed, formerly recommended by both the Cleveland and 
the Morse Twist Drill Companies, was *005 to '007 inch per re¬ 
volution for drills smaller than rr-inch diameter, and from '007 
to '015 inch for larger drills. On the other hand, experiments 
made by the Bickford Drill Company, and reported in the Ameri¬ 
can Machinist for July 24, 1902, have warranted them in adopt¬ 
ing much coarser feeds, and using them on their own machines. 

The subjoined table shows the eight feeds furnished on 
the radial drills manufactured by this firm and the corre¬ 
sponding sizes of drills :— 

Size of Drill. Feed per Revolution. 

•007 inch. 

•010 


f to | inch, 

| to 1 inch, 

1 to 1| inch, 


013 

018 

025 

035 

047 

064 


55 


5 5 


55 


55 


5 5 


55 


*5 


















DRILLING MACHINERY 


185 


lhe four finer feeds are not to be used in regular work on 
cast iron, and the coarsest feed is intended only for reaming 
and finishing. 1 ests made by the same company were carried 
to the breaking of the drill, and showed that at a speed of 
2()7 revolutions per minute a ^-inch drill could not be broken 
at the coarsest feed of the machine, '064 inch per revolu¬ 
tion. A x\"inch drill broke at this feed, and a ^-inch at a feed 
of ‘047 inch. In order that such feeds may be successfully 
used, it is necessary that the drill be held absolutely in line. 
I he breaking of drills under heavy pressures is often due to 
the springing of the arm or head which holds the spindle 
and the consequent lack of alignment. The arm of a radial 
machine may spring in two ways—first, by bending ; second, 
by twisting on account of the spindle being at one side of the 
arm. this latter is perhaps more apt to break the drill than 
the other, since the radius is less and the consequent angle 


greater 


To avoid this and get the greatest output from their 
machines, manufacturers should aim to keep the spindle as 
close to the arm as possible, and use a tubular section closed 
on both sides for the arm itself. 


104. Tables. 

Although the base of the radial drill is generally used as a 
support for the work, tables of various shapes and sizes are 
furnished when desired. The circular table mounted on a 
swing bracket is shown in Fig. 75, while in Fig. 74 we see 
the swivelling table, particularly useful with a plain radial. 
The plain box table is shown in several of the illustrations, 
sometimes mounted at the side of the base as an auxiliary. 
An elevating table, with tilting top which makes it universal, 
is used in some instances. The round column radial, such 
as is shown in Figs. 71 and 72, is sometimes fitted with a 
circular base extending around the column and having a 
radius equal to that of the arm. This makes it possible to 






186 MODERN AMERICAN MACHINE TOOLS 


get work ready for drilling on one side of the base while the 
machine is finishing work on the other, thus economising time. 
Such a machine must be driven from overhead either by a 
motor or by bevel gears. 

105. Power and Capacity. 

There has been some confusion in the rating of sizes on 
radial machines due to their peculiar construction. When 
a lathe or upright drill is spoken of in this country as having 
a swing of 36 inches, the meaning is that the machine is 
capable of finishing a piece having that diameter. 

On the other hand, a 36-inch radial drill, such as is illus¬ 
trated in Fig. 75, is a machine having a clear radius for 
drilling of 36 inches. To avoid danger of misunderstanding, 
most manufacturers prefer to designate their machines as 
3-foot arm, 4-foot arm, etc., this being understood to be the 
maximum distance from outside of column to centre of drill 
spindle. Where a column has a projecting base, this distance 
should be measured from outside of base. The flange on the 
base should be cut away, as in Fig. 72, to ensure the possi¬ 
bility of getting the entire range of the machine on heavy 
work. The electric motor is particularly serviceable on radial 
drills, as they are large machines and of such a shape that 
belt drives limit their use. 

A common arrangement is that where a constant-speed 
motor takes the place of the ordinary driving pulley, the 
changes of speed being effected by gearing. The sizes of 
motors recommended by the Prentice Company 
follows :— 


3- foot arm, 

4- foot arm, 

5- foot arm, 

6- foot arm, 

7- fcot arm, 

8- foot arm, 

9- foot arm, 


1 h.p. 

9 


3 

3 

7 

10 


? > 


* y 


are as 







187 


DRILLING MACHINERY 

Fig. 77 shows a variable-speed motor taking the place of 
the usual speed box at the base of the column, and having 
electric speed-control by variation of the field resistance. 
The same number of speeds are available as when the speed 
box is used. 

Most makers are prepared to furnish motor drives 



ELECTRIC DRIVE, VARIABLE-SPEED MOTOR. 


The Bickford Drill and Tool Co., Cincinnati, Ohio. 

either geared or connected by silent chain with the 
driving mechanism, and with either constant or variable 

speed. 

More specific information with regard to the power con¬ 
sumed in drilling may be found in a later paragraph. 


















188 MODERN AMERICAN MACHINE TOOLS 


106. Miscellaneous Machines. 


There are several varieties ol drilling and boring machines 
which do not come under any of the foregoing classifications 
and should receive separate mention. One of these is the 
wall radial, in which the column is omitted, and a radial arm, 
similar to that shown in Fig. 74, is supported on a frame 
fastened to a wall or column of the building. In the plain 
wall radial the arm always remains at the same height, while in 
the adjustable machine the arm is pivoted to a sliding saddle 
which can be raised or lowered on the frame. Even simpler 
than the above is the post drill, where a plain bracket pro¬ 
jecting from wall or post carries the drill head and spindle, 
the power feed and other complications being omitted. 

A modification of the radial drill for heavy work is the 
so-called universal drill. The arm carrying the spindle head 
is no longer radial, but is swivelled at both ends to uprights 
on either side of the bed. The uprights are joined by a top 
brace making a gallows frame, and giving rigidity to the 
whole design. The arm, now become a cross-rail, is capable 
of being raised or lowered in the frame, swivels to any 
vertical angle, and carries a swivelling head. The machine 
is thus universal, and can drill and bore at any angle. 

For drilling holes in flat plates of unlimited extent the 
suspension drill is a convenient machine. Being suspended 
from the ceiling, it leaves a clear space underneath. It is 
provided with power feed, and has eight changes of speed. 
A modification of this type sometimes used on large structural 
work has the drilling head suspended from a travelling crane, 
and capable of being moved in any direction horizontally. 
The drill is operated by an electric motor. 




107. Multiple Drill. 

Drilling machines do more work than formerly, and do 








DRILLING MACHINERY 


189 


better work because they are more rigid in construction and 
more convenient in operation. Another cause for increase of 
j output, which deserves special mention, is the multiplication 
of cutting edges in the same machine. 

Multiple drills, so called, like turret lathes, are well adapted 
to the production of interchangeable work in large quantities. 
When a casting or forging has on one face a number of 
parallel holes of the same or nearly the same size, the drill¬ 
ing of the holes simultaneously by one machine results in a 
great saving of expense if the process is repeated a sufficient 
number of times to pay for the initial adjustment of the 
machine. 

Fig. 78 illustrates a small drill press of the multi-spindle 
type, capable of carrying twelve drills from to J inch in 
diameter. The general design of the machine is especially 
neat and pleasing to the eye. The head, which holds the 
spindles, is stationary, and the feed is obtained by moving 
the table. The latter is furnished with a long bearing on the 
column, and is operated by a lever for the size shown. A 
stop, seen at the rear of the table, may be set at any desired 
point. The spindles are driven by double Hooke’s joints from 
a ring of vertical shafts above, and are so guided by adjust¬ 
able arms that they may be arranged according to almost 
any pattern. 

It is easy to set the drills in the jig to be used, to adjust 
the spindles to match, and finally to clamp the arms in 
position. Multi-spindle machines are well adapted to drill¬ 
ing holes in flanges, hubs, and couplings, and in the covers 
of cylinders and valve chests. While the illustration shows 
a small size, machines of this same type can be had in various 
sizes up to one which will drill 1^-inch holes in a circle of 
36 inches diameter. The larger machines have a stationary 
table or base and a sliding head to give the necessary feed. 

A machine having a less degree of freedom than the ones 
just described is the gang drill (Fig. 79), where the different 
spindles are arranged side by side on a cross-rail, so that the 









190 MODERN AMERICAN MACHINE TOOLS 

holes drilled come in one straight line. As may be seen 
from the figure, the cross-rail is usually stationary, and the 


Fig. 78. 

PRATT AND WHITNEY MULTIPLE DRILL. 

The Niles-Bement-Pond Co., New York. 

vertical adjustment is in the table, which can be raised and 
lowered by two screws. The heads may be from two to 























DRILLING MACHINERY 191 

I eight in number, and can be adjusted on the rail inde- 
I pendently by means ot rack and pinions. The spindles can 
j be driven and fed simultaneously by power, but are so 
I arranged that any one may be disconnected and operated 
independently by hand. The particular machine shown has 



Fig. 79. 

NILES STANDARD MULTIPLE DRILL. 

The Niles-Bement-Poncl Co., New York. 


four speeds and three feeds, and is intended for 1^ inches 
maximum diameter of drills. 

Machines of the same type are built with six or eight 
spindles driven from either end in two groups and capable of 
carrying drills 2 inches in diameter. 

























192 MODERN AMERICAN MACHINE TOOLS 

Multiple drills of this character are mostly used for drill¬ 
ing rows of holes in the edges of doors, plates, or covers of a 
rectangular shape. 

The traverse-table machine resembles a planer in general 
appearance, having a bed with two uprights and a cross-rail, 
and being equipped with a platen sliding on V-shaped ways. 
As the platen slides at right angles to the plane of the drill¬ 
ing spindles, it is possible to drill a series of rows of holes 
without re-setting the work. 

There is evidently no limit to the number of combinations 
that may be made by different arrangements of spindles, 
heads, and tables, and it would be superfluous to attempt to 
catalogue many of them here. 

The machines which have not already been illustrated and 
described can be regarded in the light of special tools 
intended for a limited range of work. The railroad car 
and locomotive shops of the country are usually equipped 
with such special tools, and some of the larger engine works 
are similarly provided for. Special lathes and boring mills 
for such shops have already been described. A large size of 
two-spindle drilling machine is intended for use on connecting 
and parallel rods and heavy work of a similar character. The 
cross-rail is stiffened by a middle upright, and the two heads 
are entirely independent of each other as regards driving and 
feeding mechanism. 

Fig. 80 shows the adaptation of the multiple-spindle 
principle to a horizontal machine for the purpose of drilling 
holes in the flanges of long pipes and columns too 
long to be handled in a vertical machine. All the adjust¬ 
ments and feeds are in the head itself, which slides length¬ 
wise of the bed, and can be controlled by power or by 
hand. Where the flanges of short columns or cylinders 
are to be drilled the machine is made with a head at 
each end, and the two flanges are drilled simultaneously. 
In such case the two heads are made entirely independent 
of each other. 









N 


The Baush Machine Tool Co., Springfield, Mass. 


















194 MODERN AMERICAN MACHINE TOOLS 


108. Power required for Drilling. 

In drilling holes through the solid metal two resistances 
need to be overcome—the vertical pressure on the point and 
the tangential resistance to cutting. Numerous experiments 
have been made by the Cleveland Twist Drill Company with 
a special drill press of their own devising, some of which were 
reported in the American Machinist for May 30, 1901. 

Tests of a 1^-inch drill, making sixty-six revolutions per 
minute and having a feed of *0075 inch per revolution, gave 
the results summarised in the following 1 table :— 

O 





Horse-Power. 


Pressure 

Tangential 



Material Drilled. 

on 

Pressure 




Point. 

at Periphery. 

Due to 

Due to 




Point. 

Cutting. 

Cast Iron, 

660 lbs. 

576 lbs. 

•0008 

•377 

Machinery Steel, 

1120 „ 

928 „ 

•0014 

•608 

Tool Steel, 

1760 „ 

1328 „ 

•0022 

•870 


Pressures, such as noted above, depend largely upon the 
way in which the drill is ground. It is to be supposed that 
the drills used in these experiments were ground as long 
experience had shown that they should be ground. It is 
apparent that, as far as power is concerned, the point pressure 
is ineffective, except in so far as it increases the friction of 
the machine. 

I he point pressure is, however, the principal factor in deter¬ 
mining the strength and rigidity of the drilling machine. 

It is in radial drills, with their long reaches and off-sets, 
that this is most apparent. From the figures just given it 
may be seen that a radial machine with a 4-foot arm would 
have a bending moment at the column of 48 x 600 = 31 ,G80 lbs. 
inches when using a 1 J-inch drill on cast iron at the full reach, 































DRILLING MACHINERY 


195 


and nearly twice this when drilling machinery steel. If the 
off-set ot spindle is 5 inches measured from the axis of tubular 
arm, the twisting moment on the arm due to point pressure 
would be 3300 lbs. inches when drilling cast iron, and 5000 
when drilling machinery steel, under above conditions. 

The actual horse-power consumed in drilling can be better 
understood from a series of experiments made by the Bickford 
Drill and Tool Company at Cincinnati, Ohio, and published 
in the American Machinist for January 14, 1904. 

'these experiments were made with drills varying from 
J inch to l|- inches in diameter and feeds varying from 
'0155 to '035 inch per revolution. The material drilled 
was cast iron, and the speed of each drill such as to give a 
cutting speed of from 30 to 35 feet per minute. Under these 
circumstances the horse-power required for each size of drill 
at the same feed was nearly the same, while the horse-power 
per cubic inch of metal per minute was much greater for the 
smaller sizes. 

The gross horse-power (i.e. including the power required 
to run the machine itself) was, in brief, as follows : — 


J-incli drill, 1 *82 to 2 79 horse-power. 
178 „ 3-06 
1-61 „ 2-89 
1-74 „ 3*30 
U „ „ 1-66 „ 3-29 


i 55 
1 „ 

n „ 


99 

>> 

99 


99 

99 

99 

99 


99 

99 

99 

99 


The horse-power per cubic inch of metal per minute 
varied from about 2 in the inch drill to about / 5 in the 
Ij-inch size. 

Experiments were also made on cast steel, wrought iron, 
and machinery steel. The following conclusions are voiced 

by the author, Mr. H. M. Norris:— 

(l) When the speed and feed are constant, the power 

required to drill cast steel is about 1T0 times, wiought non 
about 1 '65 times, and machinery steel about 1'90 times that 

required to drill cast iron. 









196 MODERN AMERICAN MACHINE TOOLS 


(2) When the speeds and feeds remain constant, the 
power required is approximately proportional to the diameter 
of the drill. 

(3) When the diameter of the drill and the rate of feed 
are constant, the power required is approximately proportional 
to the speed. 

(4) When the speed and diameter of drill are constant, 
the power required is approximately proportional to the feed. 

The horse-power per cubic inch of metal per minute is 
not far from the average in other machine tools. Tests made 
by the writer at various times have shown this to vary from 
0*5 to 2 horse-power under changing conditions when lathes, 
boring mills, and planing machines were the tools tested. 

The installation of electric motors for drilling machinery 
has shed some light on the question of power. A comparison 
of some of the installations already made shows the following 
to be current practice :— 

Machine. 

30-inch upright, 

36 „ 

40 ,, ,, 

4-foot radial, 

5 „ 

6 „ „ 

Some tests made on a 5-foot radial drill cutting cast steel 
gave 2T for the total horse-power, of which the machine 
itself absorbed IT horse-power. 

109. High-Speed Drilling. 

The use of air-hardening steel for twist drills is as yet 
rather experimental, but is destined soon to work a revolution 
in drilling, as in other machine processes. 

The reports on work of this kind come to us mostly from 
English sources, and at the present writing England seems 
to be in advance of America in this important development. 


Horse-Power of Motor. 
9 

91 

. . —/ 2 

. 3 ^ 

. 2 
. 3 

. 5 










DRILLING MACHINERY 


197 


e 

r 

1 

1 


A paper read recently at Coventry by Mr. J. M. Gledhill 
contains, amongst other interesting material, the following 
remarkable records of actual performances by twist drills 
made by A. W. Steel:— 


Diameter 
of Drill. 

Material 

Drilled. 

Speed. 

Feed. 

Endurance. 

i 

Revs. Feet 

per min. per min. 

Inches 
per rev. 

Inches 
per min. 

Inches 

Drilled. 

f-in. 

Gray Iron 

360 70 

•0167 

6 

548 

1 „ 

n 55 

250 65 

•0167 

416 

312 

1 „ 

Steel 

250 65 

•0200 

5* 

300 

1J „ 



• • • 

244 

• • • 

9 

5 5 

55 

80 42 

•0104 

0833 

620 


The author of this paper states that it is entirely possible 
to run drills at a speed of 400 feet per minute and a feed of 
25 inches per minute when cutting cast iron. 

Assuming one horse-power per cubic inch of cast iron per 
minute for a 1-inch drill, the 1-inch drill mentioned in the 
preceding table would consume about 3’25 horse-power. 

The chief advantage in the use of the high-speed steel 
seems to be in the durability of the drill, a comparison of 



G20 inches drilled by the former as against only 40 inches 
drilled by the latter. Furthermore, the ordinary drill was 
ruined by the test, while the other was uninjured. 

It must be remembered, however, that, as in other 
machines, the use of the new steels in drilling machinery 
means a re-designing of the entire tool to secure the 
increased power, speed, and strength which are necessary. 




























CHAPTER VII 







MILLING MACHINES 

no. Advantages. 


Twenty-five years ago the milling machine was regarded 
as a special tool, and the bulk of straight work was done on 
the planer and the shaping machine. To-day the milling 
machine is in the lead, and is preferred by most manu¬ 
facturers for all work within its range. The reason for this 
is the simple fact that this machine will do more work, or 
will do the same work with a greater degree of accuracy. 
The milling cutter is a multiple tool having many cutting 
edges, and it has no return motion, but cuts all the time. 
Furthermore, the possibility of shaping irregular outlines by 
one operation, and of repeating that operation, and thus 
duplicating the pattern indefinitely, gives the milling' 
machine a great advantage over machines using a single¬ 
point tool. Even in the simple operation of facing plane 
surfaces, the milling cutter with inserted teeth has made 


records which no reciprocating machine can hope to equal. 
The fact that both types of machine are to-day working side 


by side in the best shops shows that each is 
proper field, and succeeding in that field. 


finding its own 


hi. Classification. 

Milling machines may be classified in several different 
ways, according to the position of spindle, the style of frame, 
or the movement of the table. 


198 






MILLING MACHINES 


199 


(1) The spindle is usually horizontal ; vertical spindles 
being used only for special work such as profiling or die 
sinking. 

(2) The style of frame most common is the column or 
cabinet, with the table supported on a knee bracket. The 
so-called Lincoln machine has a frame similar to that of a 
lathe, with head and foot-stocks, and has a vertical adjust¬ 
ment for the spindle. The ‘ manufacturing machine 7 is 
rather a cross between the Lincoln and the column styles, 
and is used for making small parts in large numbers. A 
description has been given of the heavy machines of the 
planer type in the chapter on planing machines. 

(3) Column milling machines are classed as plain or 
universal, according to the freedom of movement of the 
table. In the plain machine the table always stands at right 
angles to a vertical plane through the spindle, while in the 
universal machines it can be swivelled to any angle in the 
horizontal plane for the purpose of milling spirals. By the 
term ‘ hand-mil lino’ machine ’ is meant one whose table feeds, 
both vertical and horizontal, are operated by hand. 

112. Column Machines. 

In discussing the details of milling machines, all those 
having column or cabinet frames will be considered together 
since they possess the same general characteristics. The 
elements of such machines are—(<x) the column and its base; 
(, b ) the table and its supporting bracket; ( c) the spindle and 
head ; ( d) the driving mechanism ; (e) the feed mechanism ; 

( f) the various attachments for head and table. 

113. The Column. 

The rectangular cabinet similar to that already described 
in the chapter on shaping machines is in almost universal 
use. It assumes various shapes, according to the size of the 








Fig. 81. 

NO. 14 PLAIN MILLING MACHINE. 

The Kempsmith Manufacturing Co., Milwaukee, Wis. 












MILLING MACHINES 


201 


machine, from the slender proportions in the hand machine 
to the massive contours of the one shown in Fm. 82, but 
the general design is the same in all. Some builders prefer 
to make the base slope smoothly to the floor, as in the last- 
named figure, while others make it with a rim to catch oil 
and chips, as in Fig. 81. The head is in nearly all cases 
cast directly to the column without any dividing ridge or 
moulding. Two bevelled ways on the front surface are guides 
for the bracket which supports the table. Weight and 
stability are the main features of the design, and these are 
particularly necessary in a machine so prone to chatter as 
the milling machine. Small machines are provided with an 
oil pan underneath the table, and all the machines shown 
have closets and shelves for convenience’ sake. 

114. The Table. 

In the column type of machine the head is stationary, the 
cutter revolves in one plane, and all the motions for adjust¬ 
ment and for feed are in the table. As has already been 
noticed, the principal support of the table is a bracket or 
knee as it is generally called, sliding vertically, with gibbed 
bearings on the front of the column. The gibs are tightened 
by clamp bolts and levers, so as to hold the knee firmly at 
any height. The vertical adjustment is effected by a screw 
underneath. This latter is made telescopic in most machines, 
so that it is unnecessary to have it run through the floor, as 
may be seen by reference to several of the illustrations. A 
ball bearing is frequently used to take the thrust of the 
elevating screw. The hand wheel for operating the screw 
is shown clearly in Fig. 84 standing obliquely at the left of 
the knee. The knee has a long bearing on the column, and 
is braced underneath by triangular or parabolic flanges. 
Bevelled ways on top of the knee guide the saddle, which 
slides to and from the column parallel to the spindle. The 
saddle is actuated by a screw, and in all the larger machines 


202 MODERN AMERICAN MACHINE TOOLS 


the feed is automatic. When the table alone is to be fed, the 
saddle can be clamped in position. 



Fig. 82. 

NO. 3 PLAIN MILLING MACHINE. 

li. K. Le Blond Machine Tool Co., Cincinnati, Ohio. 


W e come now to the parting* of the ways between the 
plain and the universal machines. In the former, illustrated 













MILLING MACHINES 


203 


in Figs. 81 to 83 inclusive, the table slides directly on top of 
the saddle in dovetailed ways provided for that purpose, and 
as a consequence always moves at right angles to a vertical 
plane through the axis of the spindle. On the other hand, 
in the universal machine a turn-table is mounted upon the 
saddle and carries upon its upper surface the guides for the 
table. The latter can thus be swivelled so as to travel at any 
angle in the horizontal plane and permit oblique and spiral 
forms to be cut. While the universal machine is indis¬ 
pensable for certain classes of work, it is not so good a 
machine for the ordinary work of the shop as its relative. The 
introduction of the extra joints complicates the feed mechanism 
and makes the table less firm, while the space occupied by 
the turn-table reduces the vertical capacity of the machine. 

The swivel or turn-table can be set 45 degrees either 
side of the middle position without disturbing the automatic 
feed of the table. It has a large bearing surface on the 
saddle, and can be clamped in any position by bolts. 

The table in all machines, plain or universal, is much the 
same in design, being a box-casting with the conventional 
dovetail slide at the bottom, and with slots for bolts at the 
top. It has an automatic feed on the saddle, and can be 
clamped at any desired position. The front edge is slotted 
for adjustable blocks, which act as automatic stops to the 
feed motion. To sum up, the table has three motions, any 
or all of which can be made automatic at will, while the 
universal table has in addition the swivelling motion. 

The various hand wheels and cranks for controlling all of 
these various feeds and adjustments are so located as to be 
easdy reached from the front oi the machine, a leatuie which 
is to be especially commended. 

115. The Spindle and Head. 

The character of the work which a milling machine is 
called upon to do necessitates particular care 111 the design ot 





204 MODERN AMERICAN MACHINE TOOLS 

the spindle that it be true and rigid, and that its bearings 
may always be in line as they are adjusted for wear. 

Spindles as a rule are made of crucible steel having a 



Fig. 88. 

NO. 4 PLAIN MILLING MACHINE. 

Cincinnati Milling Machine Co. 


rather high percentage of carbon, with journals accurately 
ground to size and running in bronze or babbited bearings. 

Experiment and practice has brought about a practically 
uniform design for the bearings of the spindle. The front 
journal is conical, and adjustment is effected by crowding it 

















MILLING MACHINES 


205 


back in the bearing. I lie rear journal is straight, having a split 
box fitting a conical hole in the head, and adjusted by lock 
nuts at each end. Fig. 85 shows the method of adjustment of 
the front bearing. A lock nut on the inner end of the box 
crowds back the spindle by pressing on the hub of the face gear. 

The spindle, as it wears, is thus kept accurately in line. 
It has a hole through it from end to end, and is fitted at the 
front end with a standard taper hole for arbors and an 
external thread for chucks. This thread, when not in use, is 
protected by a cover nut, and a dust cap on the end of the 
spindle protects the bearing from dirt. 

Nearly all milling-machine heads are at the present time 
equipped with an overhanging arm for the purpose of steady¬ 
ing the outer end of the arbor. This is hung in bearings 
cast to the head above the spindle, and can be adjusted for 
different lengths of arbor or turned entirely out of the way 
when light work is being done. In the smaller machines 
the arm takes the form of a goose neck at the end. The 
support for the arbor in the heavier machines is a separate 
casting bored to fit the arm, and sometimes two of these are 
provided, as shown in Fig. 83. Both supports are fitted with 
bronze bushes, which are split and can be adjusted to a snug 
bearing on the arbor. The arm itself in such cases is usually 
made of steel, and has a long bearing in the head, with 
powerful clamping bolts. (See also Fig. 82.) A machine 
sometimes has one arm with two bearings, one a bush and 
one a centre, for use on heavy and on light work. To further 
stiffen and strengthen the machine when taking heavy cuts, 
braces are attached to the front arbor support, connecting 
it firmly with the saddle, as in Fig. 81, or with the knee 
itself, as in Fig. 82. When the work and the arbor are 
properly adjusted, these braces can be set in place and bolted, 
making practically a footstock for the machine, and increas¬ 
ing the stiffness in a marked degree. Fig. 83 shows still 
another arrangement, where the brace is bored for the end of 
the overhanging arm. 



206 MODERN AMERICAN MACHINE TOOLS 


In some of the larger sizes of machines the braces are 
carried to the base of the column and serve to stiffen the 
knee as well as the arm. 

The whole design of the spindle, the head, and their 
attachments is such as to afford a firm support and perfect 
alignment for the cutter when doing the heavy and rapid 
work which modern manufacturing methods demand. 


116. The Driving Mechanism. 

Speed cones, usually of four steps, are employed in the 
same manner as on lathe spindles, and are used in combina¬ 
tion with double gears to obtain the desired speeds. A two- 
speed countershaft raises the number of different speeds to 
sixteen. The machine shown in Fig. 82 is double back- 
geared, with three steps on the cone, thus having nine speeds 
for each countershaft speed, or eighteen in all. There is a 
friction device for throwing in the back gears so that speed 
can be changed quickly. 

In all the geared machines shown shields are provided to 
cover the gears and prevent accidents. 

The speeds provided for depend, of course, upon the size 
and capacity of the machine. Tiie standard dimensions 
recently agreed upon by American manufacturers, and closely 
representing current practice, are as follows 


Plain Milling Machines. 


No. of Machine. 

0 

l 

4 

2 

3 

4 

5 

Transverse movement, 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

6 

7 

hr 

7 

8 

10 

12 

12 

A r ertical movement, 

15 

19 

19 

19 

20 

20 

21 

Automatic table feeds, 

18 

24 

24 

28 

34 

42 

50 




















MILLING MACHINES 


207 


Universal Milling Machines. 


No. of Machine. 

1 

U 

2 

3 

Transverse movement, 
Vertical movement, . 
Automatic table feeds, 

7 in. 

18 in. 

20 in. 

7 in. 

18 in. 

20 in. 

8 in. 

18 in. 

25 in. 

10 in. 

19 in. 

30 in. 


A comparison of three different makes of plain machine 
gives the following as about the average speeds recom¬ 
mended : — 


Spindle Speeds. 


No. of Machine. 

0 

1 

0 

3 

4 

5 

Changes of speed, 

8 

8 

16 

16 

16 

18 

SloAvest speed, . 

60 

60 

16 

12 

10 

10 

Fastest speed, . 

360 

300 

400 

360 

360 

360 


The speeds are given in revolutions per minute. Each set 
of speeds is supposed to form a series in geometrical progres¬ 
sion. Surface speeds of from 20 to 60 feet per minute are 
recommended, depending upon the nature of the material and 
the character of the cut. 

The subject of high-speed milling will be discussed in the 
latter part of this chapter. 


117. Feed Mechanism. 

It is in the range and power of the feeds that there has 
been the most conspicuous improvement of late years. For¬ 
merly an automatic feed for the table controlled by small 
cone pulleys of three steps was all that was considered neces¬ 
sary. To-day all the feeds are automatic, have an extended 






























208 MODERN AMERICAN MACHINE TOOLS 


range of speeds, and in the heavier machines are positively 
driven by gears. The use of the double Hooke’s joint with 
telescopic shaft is almost universal as a means of driving the 
table mechanism in all its different positions. In Fig. 81 is 
shown a gear box driven by chain from the spindle and 
having sixteen changes controlled by three levers. The 
speed boxes are similar to those already noticed on lathes 
and drilling machines, and are gradually supplanting belt 
feeds in all machine tools for heavy service. 

Machines such as the one shown in Fig. 82 have belt feeds 
in No. 2 and smaller sizes, but gearing in the larger ones. 
With the gear box shown in the cut sixteen changes can be 
obtained by the use of two levers. 

The machine illustrated in Fig. 83 has an inclined shaft 
and bevel gears which transmit motion from the spindle to 
the lower gear box. One change lever is located at the top 
giving two speeds, and the other changes are obtained by 
levers at the gear box. The machine shown in Fig. 84 has 
the feed actuated by a chain. 

There is some variation in the feeds specified by the 
different manufacturers of milling machines, the finest being 
from ‘002 inch to '007 inch and the coarsest from '15 inch to '35 
inch per revolution, the latter figure being for large machines 
like No. 4 or No. 5. There are from twelve to twenty 
changes of feeds, according to the make of machine, the feeds 
like the speeds increasing in geometrical progression. The 
reason for this is apparent when one considers that the 
cutting speed depends on the size of the cutter as well as 
the number of revolutions. With a small cutter and a high 
spindle speed a fine feed per revolution of spindle is desired ; 
while with a large cutter and low spindle speed a coarse feed 
is needed to give the same travel of table per minute. The 
following tables are copied from the plates attached to a 
Brown and Sharpe No. 2 Universal Milling Machine and 
show the speeds and feeds available and the manner in which 
they are obtained :— 




Fig. 84. 

NO. 3 UNIVERSAL MILLING MACHINE. 

Brown and Sharpe Manufacturing Co., Providence, 11.L 


o 









210 


MODERN AMERICAN MACHINE TOOLS 


Spindle Speeds. 


Back Gears. 

In. 

Back Gears. 

Out. 

Counter Reverse. 

Counter Reverse. 

Slow. 


Fast. 

Slow. 


Fast. 

16 

17 

19 

79 

88 

96 

24 

26 

29 

118 

131 

144 

35 

39 

43 

175 

194 • 

212 

53 

58 

64 

262 

290 

318 


Table Feeds. 


Feeds per Revolution 

or Spindle. 

Levers. 

Left. 

Right. 

■ i 

o 

o 

co 

•004 

•005 

•006 

•007 

Up 

Up 

•017 

•014 

•012 

•010 

•008 

Up 

Down 

•021 

•026 

•031 

•039 

•047 

Down 

Up 

•120 

•100 

•083 

•067 

•055 

Down 

Down 

1 


In other words, the modern operator has at his control, 
by the shifting of one or two levers or possibly a belt, 24 
speeds and 20 feeds, and has small excuse for not using the 
ones best suited to the work in hand. 

The feed motions are transmitted from the gear case 
through the Hooke’s joint to another gear case on the saddle, 
where is usually located the starting lever by which the feed 
can be reversed or started in either direction. The further 
transmission to the two or three screws which operate the 
table and its supports is necessarily rather complicated, 
especially in the universal machines, where the table feed 
must be driven from the centre of the swivel. No attempt 










































Purged Cnicible Steel Spindle 






»WMOH 


Fig. 85. 

DETAILS OF SPINDLE. 

Cincinnati Milling Machine Co. 

118. Attachments. 

The milling machine, and more especially the universal 
machine, is to a large extent dependent upon the various 


MILLING MACHINES 


will be made here to describe these in detail, but attention 
will be called to results. On most machines of the No. 2 
size or smaller, only the longitudinal and transverse feeds are 
automatic, but the larger sizes have also a power feed for the 
elevating screw. The hand-wheels or cranks controlling the 
various feeds directly, are fitted with clutches which can be 
disengaged when the wheel is not in use and thus prevent 
danger of the adjustments being disturbed. The hubs of 
all hand-wheels have graduated dials to facilitate accurate 
adjustment. Trip motions are provided for the table feed, 
operated by dogs on its front edge. There is a quick return 
for the table with a hand-wheel, located preferably at the 
right end. 


c 

a_ 

ao 









































































































212 


MODERN AMERICAN MACHINE TOOLS 


special attachments which hold and control the work. When 
a plain machine is at work on plain pieces, little is needed 
more than the usual chuck or vice, but when it is necessary 
to cut flutes or spirals upon cylindrical or conical pieces, more 
elaborate devices must be had. The remarkable record of the 
milling machine is due as much to improvements in the table 
attachments as to those in the machine itself. 

119. The Universal Head. 

The so-called universal head can be used on all machines 
as a dividing or indexing head, while on universal machines 
it may be used for cutting spirals by being geared to the 
lead screw of the table. 

It may be well to state here that the term spiral as used 
by American manufacturers means a helix and not a flat 
spiral. 

To illustrate one form of the universal head, reference is 
made to Fig. 86, which shows the details of such a head as 
used on the Cincinnati Milling Machines. It is shown 
clamped on the table of a universal machine, so that its 
spindle is parallel to the lead screw. The head and table 
may then be swivelled to such an angle with the spindle of 
the machine as to bring the cutter tangent to the spiral 
desired. The head spindle is shown geared to the lead screw 
by change gears to give the proper rotation and translation 
for the spiral. The indexing or dividing mechanism turns 
the spindle by means of the worm and wheel shown in the 
two latter views. 1 he worm turns in an oil-bath, and can be 
disengaged when not wanted by dropping down one bearing. 
When plain or direct indexing is to be done, the worm is 
disengaged and an index plate on the front end of spindle is 
used. 

For bevel or taper work the entire head can be swivelled 
about a horizontal axis, perpendicular to the spindle, without 
disturbing the relations of the driving gears or indexing 


MILLING MACHINES 


213 


mechanism. The trunnions on which it turns are nearly the 
full size of the head and can be clamped by the circular straps 
embracing them. The head can be turned from 10 degrees 
below the horizontal to 50 degrees beyond the vertical, or 
150 degrees in all. The centre of the tailstock can be raised 
or lowered, and can be swivelled 10 degrees above or below 
the horizontal to accommodate taper work. 

The Brown and Sharpe style of head may be seen in 
position on the machine shown in Fig. 84. It possesses 
adjustments and movements similar to those just described. 
Special heads are sometimes designed for spiral milling with¬ 
out the swivelling attachment and with a simpler indexing 
mechanism than is found in the universal head. 

On the other hand, indexing heads are made for use on 
plain milling machines, without any automatic driving 
mechanism and without any swivel. These are suitable 
and convenient for straight work. Briefly, a head may be 
capable of cutting straight flutes on cylinders, of cutting 
spirals on cylinders, or of cutting either straight or spiral 
flutes on either cylindrical or conical surfaces. 

120. Chucks and Vices. 

The vice for holding work which cannot be placed on 
centres may have one or more degrees of freedom. The plain 
vice, similar to that used on a shaper, has no adjustment, 
except opening and closing on the work. The swivel-vice, as 
its name implies, allows the work to rotate in a horizontal 
plane, the swivel being graduated to degrees. A circular 
milling attachment can be fastened to the table of any 
machine, and consists of a circular platen furnished with 
slots for bolting on the work, and capable of being rotated 
by a worm and wheel. An automatic rotary feed can be 
attached if desired, but the hand-wheel is generally used. 
The circumference of the platen is graduated, and it may be 
locked in any desired position. This device is particularly 






NEW UNIVERSAL DIVIDING HEAD. 























































































































































































MILLING MACHINES 215 

convenient when used in connection with a vertical milling 
attachment. 

121. Spindle Attachments. 

Arbors are furnished in different lengths and diameters. 
They fit a standard taper socket in the end of the spindle, 
and are forced out either by a nut on the shank of arbor or 
by a screwed rod in the hollow spindle. Collets of various 



Fig. 8(3 b . 

shapes and sizes can be fitted to the spindle foi holding 
small mills and end-cutters. Several attachments have been 
brought out by various manufacturers for performing special 
operations other than ordinary milling, such as vertical 

milling, slotting, and cam-cutting. 

While these attachments will undoubtedly do what is 
claimed for them, they will not do it as well as a special 
machine, and can only be tolerated in a small shop for inter¬ 
mittent jobs. The manufacturer who wishes to do profiling 
or slotting or cam-cutting in any quantity had better buy 
machines better adapted to these special operations than the 
ordinary milling machine. 













































































































































21G MODERN AMERICAN MACHINE TOOLS 


Such attachments are usually bolted to the face of the 
headstock near the spindle, and are driven by a special 

arbor. The vertical 
milling attachment 
consists of a vertical 
spindle, running in ad¬ 
justable bearings and 
driven through mitre 
gears from the spindle. 
It is capable of being 
swivelled in a vertical 
plane to any angle. 
The attachment is 
steadied by a special 
support on the over¬ 
hanging arm. The 
slotting attachment is 
supported in a similar manner, and carries a slotted crank 
and pitman for driving a vertical slotting head. 

The rack-cutting attachment, on the other hand, drives a 
horizontal arbor at right angles to the spindle in such a way 
as to cut racks which lie lengthwise on the table and thereby 
cut them of any length. Such a device, used in connection 
with the universal machine, makes it possible to cut wide 
spirals whose angle is greater than 45 degrees. 




Bolt for 
clarcj>lng swivel 
Block ^ 



Fig. 86c. 


122. High-Speed Milling. 

Most manufacturers recommend cutting speeds for the 
milling machines of 20, 40, and GO feet per minute when 
milling steel, cast iron, and brass respectively. There is no 
accepted standard for feed of the table in inches per minute, 
and the feed per revolution of spindle varies from 3-thousandths 
to as many tenths of an inch. Perhaps from 3 to 6 inches 
per minute may be considered ordinary table speeds for cast 
























































































MILLING MACHINES 


217 


iron. The above speeds and feeds are for ordinary carbon- 
steel milling cutters. 

It is undoubtedly true that better results can be obtained 
by using coarser feeds than usual; in other words, by having 
as thick a chip as possible per tooth of cutter. Increasing 
the surface speed of cutter will shorten its life ; but increasing 
the table feed will not usually injure the cutter, although it 
may stall the machine. Table feeds of from 10 to 15 inches 
a minute have been successfully used of late. The following 
table sums up some results published by the Cincinnati 
Milling Machine Co., and gives a good idea of advanced 
practice in the United States :— 


Kind of 
Milling. 


Slab, . 

Slab, . 

Face, . 

Face— \ 

Finishing, i 
Gang,. 

Gang— | 

Finishing, J 
Gang,. 
Spiral, 

Spiral— \ 

Finishing, J 
Slab, . 
Spline, 



Width of 
Cut. 
Inches. 

Depth of 
Cut. 
Inches. 

Speed of 
Cutter. 
Feet per 
Minute. 

Table Feei 

D. Inches. 

Material 

Cut. 

Per 

Revolu- 

Per 





tion of 
Spindle. 

Minute. 

Cast iron 


1 

8 

40 

•252 

8-50 

0 n 

61 

•3 

3 2 

40 

T68 

5-75 

55 O 

H 

1 

8 

40 

T38 

263 

55 55 

A 3 
*16 

• • • 

60 

•252 

13 00 

5 5 5 5 

Ql 

1 

8 

40 

•075 

2-32 

5 5 5 5 

• • • 


40 

TOO 

1-25 

5 5 5 5 

Tool steel 

75 

1 8 

f top 

3 

"ST 

1 

2 

47 

■075 

■025 

3-00 

0-75 





•036 

1-08 

55 55 







5 

1 

44 

•050 

2-8 

55 55 

Mch. ,, 

4xJ 

¥ 

8 

40 

•075 

4*5 


123. Lincoln Milling Machines. 

By the term Lincoln machine is meant one in which 
there are two housings or supports for the arbor, on which 
the latter can be adjusted vertically, the table having no 
































218 MODERN AMERICAN MACHINE TOOLS 


vertical adjustment. Fig. 87 shows the principal charac¬ 
teristics of this class of machine. It is not so universal in 
its adaptations as the machines just described, but is a 
convenient machine for duplicating small pieces in large 
quantities. It is compact and rigid, and is so arranged as to 
be convenient for the operator. One housing is broad and 
stiff, carrying the driving spindle, while the other is more 
slender, merely forming a support for the outer end of arbor. 
These are joined at the top by an arm which carries a third 
intermediate support for the arbor. 

It is evident from this construction that the machine is 
particularly firm and stiff. The spindle head is intended to 
be locked in position when the machine is running. Fig. 88 
illustrates a large duplex machine of this same class, or rather 
a cross between the Lincoln machine and the planer type. 
This milling machine has revolving spindles on each housing, 
which are independent of each other. The housings can be 
adjusted independently on the bed, and the heads adjusted 
independently on the housings. For greater rigidity the bed 
is extended to support the platen, much the same as in a 
planing machine. The result is a massive, strong machine, 
well adapted for heavy roughing work on forgings or castings. 

The machine can be used for slabbing cuts, or by mount¬ 
ing face plates with inserted teeth on the spindles it becomes 
a rotary planer. 


124. The Manufacturing Machine. 

This term has come to mean a small machine, especially 
adapted for making large quantities of some particular piece, 
and is generally used for a few operations many times 
repeated. 

The spindle head, in this case, is pivoted to a standard at 
the rear, and can be moved up and down in a circular arc. 
It is guided by segments on two standards in front, and can 
be clamped to these at any desired position. The spindle is 




Fig. 87. 

LINCOLN MILLING MACHINE. 


The Kempsmith Manufacturing Co., Milwaukee, Wi$. 








220 


MODERN AMERICAN MACHINE TOOLS 

driven bv gearing from tbe pulley shaft, the axis of the lattei 
coinciding with the pivots on which the head swings. I he 
overhanging arm is similar to that on any plain milling 
machine, is supported by an outside brace or yoke, and carries 
the usual arbor support. The table slides in ways planed 



Fig. 88. 

DUPLEX MILLING MACHINE. 

Newton Machine Tool Co., Philadelphia, Pa. 


directly in the bed, and has, consequently, no transverse 
motion. 

The feed for the table is automatic, and is driven by gears 
from the pulley shaft, three changes being a vailable. 






MILLING MACHINES 


221 


125. Profiling Machines. 

If it becomes necessary to outline the edges of a flat piece, 
or to cut grooves or recesses of any shape in the face of such 
a piece, the vertical spindle is much more convenient than 
the horizontal, because it permits the work to be clamped flat 
on the table where all the outlines can be clearly seen. The 
vertical spindle machine is frequently called a profiling 
machine, in view of the uses just mentioned. 

The characteristics of such a machine are high speed 
and careful alignment of spindle. Such work as has been 
described must be done by an end-cutting mill, or at least 
by one with a free end, and this fact makes it all the more 

1 necessary that the bearings of the spindle should be carefully 
adjusted. Fig. 89 illustrates a two-spindle profiling machine, 
and Fig. 90 the details of the spindle bearings and gearing. 

The spindle is hollow, with a rod for holding and for 
ejecting the mill. The lower bearing is conical, with a lock 
nut above to draw back the spindle, and a rotating washer 
below to take the end thrust. The upper bearing is cylin¬ 
drical, and being split, is adjusted for wear by the lock nuts 
shown. 

The spiral gear at the centre, which gives the motion, 
runs in bearings of its own independent of the spindle, so 
that the latter is relieved from all side pressure. This con¬ 
struction also permits adjustment of the gears to take up 
> back-lash, without disturbing the alignment of the spindle. 
The ball-thrust bearings shown take the end pressure, due to 
the action of the spiral gear. The other gear is supported in 
a similar manner, and both gears run in a tight casing filled 
with lubricant. This construction relieves both spindle and 
shaft of all side pressure, and permits the use of high speeds. 
It is possible, with the machine shown, to run at a speed of 
1200 revolutions per minute. 

The particular machine illustrated in Fig. 89 has two 





22*2 


MODERN AMERICAN MACHINE TOOLS 
spindles, the intention being to use a roughing cutter in one, 



Fig. 89. 

TWO-SPINDLE PROFILING MACHINE. 

The Pratt and Whitney Co., Hartford, Conn. 


and a finishing cutter in the other. This will permit finishing 
the work without resetting and without changing the cutter. 




















MILLING MACHINES 


223 


Each head is adjustable vertically in the saddle, and is held 
up by a heavy spring. Micrometer adjustments and suitable 
stops make it possible to gauge the exact depth desired in 
work like die-sinking. 

The saddle can be fed along the cross-rail by means of the 
rack and pinion shown, controlled by the large crank at the 
right of the table. The table is fed transversely in a similar 
manner by the left-hand crank. The operator can thus 
manipulate the machine readily from his position in front. 

Since lost motion of any kind is particularly objectionable 
in this kind of work, provision has been made to eliminate it 
by using double racks and pinions on both table and cross¬ 
rail. The two parts are mutually adjustable, which has the 
etfect of widening the tooth and taking up all back-lash. 

The other details of this machine may be seen from the 

cut. 

126. Vertical Milling Machines. 

Fig. 91 shows a vertical machine less restricted in its 
operation than the one just described. In fact, this machine 
is the same as the ordinary plain column milling machine, 
with this one exception, that the spindle is now vertical. 

An examination of the illustration will show the details 
of column, knee and table, to be almost identical with those 
in the horizontal machine. No particular attention need be 
given these details, but the peculiar characteristics of the 
vertical type will be noticed. 

The spindle is carried on a head which has a slight 
vertical movement, controlled by a spring and by the foot 
lever shown. This leaves the hands of the operator free to 
manipulate the table. To relieve the belt pull on the spindle 
and preserve its alignment an auxiliary support is bolted to 
the top of the frame. This is open on the front, and can be 
adjusted at the back to take up any wear that may occur. 
A rotary milling attachment is shown in the illustration, 
bolted to the table and connected with the automatic feed by 



224 MODERN AMERICAN MACHINE TOOLS 


gearing. The machine is intended for use with small cutters 
at high speeds. By using a small pulley on the spindle, 
speeds as high as 4000 revolutions per minute can be obtained. 





Fig. 90 . 

DETAIL OF SPINDLE. 

The Pratt and Whitney Co., Hartford, Conn. 

While more universally adaptable than the profiling 
machine, the vertical milling machine is not so convenient 
as the former for hand manipulation, since it has more lost 
motion in the joints and does not have as handy an arrange¬ 
ment of feed cranks. Some of the small milling machines are 




































































MILLING MACHINES 225 

furnished with rack feed for the table, as better for rapid 
i work. 


Fig. 91. 

VERTICAL MILLING MACHINE. 

The Becker-Brainard Milling Machine Co., Hyde Park, Mass. 

! j n Fig. 92 is shown one of the larger sizes of vertical 
I machine adapted for heavy work. The cabinet is massive 

p 







226 


MODERN AMERICAN MACHINE TOOLS 

and supports the table directly, while the head is mounted 
on a circular column cast to the rear of the cabinet. A novel 
adjustment of the head is obtained by making the column 
telescopic. The inner column carrying the head is raised or 
lowered by the wheel shown hack of the table at the right. 
There is also a micrometer adjustment of the spindle in the 
head, operated by the hand-wheel shown. 1 lie spindle is 
driven by a chain inside the casting from the vertical shaft 
shown in the cut, and is provided with special devices for 
holding positively large or small cutters. The whole head 
is of a good design to ensure strength and rigidity. 

The table is mounted on a saddle, and that in turn on flat 
ways cast to the bed. Both longitudinal and transverse 
feeds are controlled by hand-wheels at the front of the 
machine. Both feeds are automatic, and can be varied by 
a gear-box similar to that used on the horizontal machine. 

The machine shown in the illustration is back-geared, has 
12 changes of speed, and 40 changes of feed, varying from 
*002 inch to 0*6 inch per revolution of spindle. 

A comparison of these machines with some of the boring 
and drilling machinery already described will disclose a 
marked resemblance. A drilling machine with automatic 
feeds to the table is very near to being a milling machine, 
and a vertical milling machine with a circular milling attach¬ 
ment is very like a boring mill. Perhaps the most marked 
characteristic of the milling machine is the rigidity and com¬ 
parative restraint of its spindle. As a rule, the milling 
spindle, like the lathe spindle, revolves steadily in its bear¬ 
ings, and the work must come to it. 

127. Power and Capacity. 

Some data with regard to the limiting speeds and feeds 
of milling machines have been given in a previous paragraph, 
but reliable figures for the amount of power needed are hard 
to find. Such experiments as have been made with the aid 


MILLING MACHINES 


ot dynamometers, show that the ordinary spiral milling cutter 



Fig. 92. 


NO. 5 VERTICAL SPINDLE MILLING MACHINE. 

Brown and Sharp? Manufacturing Co., Providence, R.I. 

consumes more power per cubic inch of metal removed than 
* the lathe of the planer. 

This is doubtless generally true since the shape of tooth is 













228 MODERN AMERICAN MACHINE TOOLS 


not so favourable for the removal of chips without friction as 
that of the diamond point. 

Professor Flather reports the consumption of T4 h.p. per 
pound of cast iron per hour, which is three or four times as 
much as would be required by a good engine lathe. The 
writer once found in testing a large gap lathe values ranging 
from T2 to T6 h.p. per pound per hour when using an 
inside tool, a somewhat analogous case. 

Probably large machines employing inserted cutters would 
show much lower values. The Hess Machine guarantees 
with one of its heavy milling machines and special cutters a 
roughing cut on cast iron 42 inches wide, |>-inch deep, and 10 
inches feed per minute, making 210 cubic inches, or 54 pounds 
of metal per minute. 

Mention is also made of cutting 36 inches wide, |Hnch 
deep, and 8 feet long in 30 minutes or 57 cubic inches per 
minute. 

The following sizes of motors were recommended for milling 
machines to be used in a railway shop :— 


Heavy slab, milling machine, 

Heavy vertical, ,, ,, 

Smaller vertical, ,, ,, 

Heavy universal, ,, ,, 

Plain horizontal, ,, ,, . No. 14 

Small plain, ,, ,, 

Small universal, ,, ,, . No. 3 


Motor H.P. 
15 
10 
75 
5 
4 

2-5 

1 








CHAPTER VIII 


GEAR CUTTING 

128. Gear Cutting in General. 

At the present time it is not necessary to make any argu¬ 
ments for the use of cut gears in preference to those in which 
the teeth are cast. In all improved machinery cut gears are 
now the rule, and the only question at issue is how to cut 
them the most accurately and cheaply. 

Gear-cutting machines may be classified as follows: 
(l) plain machines indexed by hand; (2) automatic gear 
cutters of the milling machine class; (3) gear shapers where 
the tooth outline is generated automatically; (4) gear 
planers used particularly for bevel wheels. To this list may 
perhaps be added the thread milling machine, considering 
the screw thread as the tooth of a spiral gear. 

The arguments for the use of one or the other of these 
machines will be discussed later. The plain gear-cutter with 
a hand index needs no description, since it is merely a plain 
milling machine adapted for this particular purpose. 

These machines can be run in gangs and several of them 
managed by one attendant. Where stock gears are made in 
considerable quantities, it is well to have a separate machine 
for each size and kind of gear, the index wheel containing just 
the same number of holes as the wheel has teeth. This 
makes it possible to cut teeth at random around the wheel 
and avoid uneven heating. This is especially desirable in 
large gears. It is a well-known fact that stopping a machine 




230 MODERN AMERICAN MACHINE TOOLS 

which is cutting teeth in regular rotation around the wheel 
will produce a jog or irregularity on account of the heating 
and cooling of the metal. 

One man or boy can attend a large number of machines 
arranged as just described, and turn out nearly, if not quite 
as much work as with the automatic machines. 

129. Automatic Machines. 

Where a large variety of wheels are to be cut, especially if 
they be of small size, the automatic machine is almost a neces¬ 
sity for economical production. 

An automatic gear-cutter means one which will perform all 
the operations of cutting and indexing automatically, when 
once the blank is put in place, the cutter adjusted and the 
machine started. These may be had in all sizes ranging from 
the smallest machine which cuts pinion teeth on a rod 

-g- inch in diameter, to the largest machine intended for gears 
8 or 9 feet in diameter. 

In discussing these different machines it will be necessary 
to consider each by itself, since there is not the same family 
resemblance as among lathes or planers. The Slate auto¬ 
matic machine intended for small gears from ^ inch to 

4 inches in diameter and cutting teeth from 50 pitch to 16 
pitch, has the arrangement of cutter spindle and work 

spindle the same as in the ordinary plain milling machine, 
the former being above the latter. In fact the machine can 
be used for making reamers and other circular cutters as well 
as for gears. 

The work can be held in a chuck or on centres according 
to its character. 

The index head is firmly locked in position while the tooth 
is being cut and is then turned automatically to the next 
position. 

The feed of the table which carries the work is operated 
by a cam at the right end which gives a slow advance and a 



GEAR CUTTING 


231 


quick return. The cam works against a roll on the slotted 
lever or crank, and this in turn is connected with the table by 



Fig. 93. 

36-INCH AUTOMATIC GEAR CUTTER. 

The Becker -Brainanl Milling Machine Co., Hyde Bark, Mass. 


an adjustable rod. It is thus possible to use the same cain 
for different lengths of stroke, and by varying the radius ot 




232 MODERN AMERICAN MACHINE TOOLS 


crank any desired stroke can be obtained. After this has 
been done, the length of rod is adjusted to bring the work in 
the right relation to cutter. The cutter can be thus 
arranged to just clear the work at each end of stroke and 
time be saved. The return of the table is effected either by 
a coiled spring or by a weight. 

The feed is thrown out of gear automatically at the comple¬ 
tion of the work. The operations of reversing and indexing 
the machine consume from one to five seconds’ time according 
to the speed at which the machine is running. 

When larger gears are to be cut the work and the divid¬ 
ing wheel are usually mounted upon the main spindle of 
the machine while the cutter is carried upon the table, thus 
reversing the arrangement just described. 

Fig. 93 shows a machine of this style adapted for cutting 
gears up to 18 inches in diameter. 

The general appearance is still that of the milling machine 

with a pillar support. The overhanging arm is present, being 

used to support the outer end of the work mandrel. At the 

rear end of this mandrel is located the index or dividing 

© 

wheel, and this is operated automatically by a train of gears. 

The table which carries the cutting mechanism is universal; 
it can be raised and lowered to give the right depth of cut by a 
screw with micrometer attachment; it can be tipped vertically 
from 0 to 90 degrees for cutting bevel gears and can be set at 
any angle horizontally for cutting spirals. The automatic 
feed is parallel to the spindle of the machine and in the 
plane of the cutter. 

Return is made at a speed forty times that of the advance 
without any change of direction of the belting and pulleys. 

The feed can, however, be disconnected by a clutch and 
the machine be adjusted or fed by hand. There is also an 
arrangement by which the wheel to be cut may be turned 
one way or the other without disturbing the indexing 
mechanism, as is necessary in cutting bevel gears when a 
change is to be made from one side of the tooth to the other. 




GEAR CUTTING 


233 


This particular machine 


is intended to cut gears lip to 18 



Fig. 94. 

48-IXCH AUTOMATIC GEAR CUTTER, 

The Brown and Sharpe Manufacturing Co., Providence, R.I. 

inches diameter, 4 inches face, and 6 pitch, and lias a rate 
of feed of from 2 to 7 inches per minute. 



















234 MODERN AMERICAN MACHINE TOOLS 


The need of greater rigidity in the frame where large gears 
are to be cut has led to a decided modification in the design, 
as may be seen by reference to Fig. 94. This machine is 
designed to cut gears up to 48 inches diameter and 9 
inches face, with 4 pitch teeth. In general appearance it 
resembles a horizontal boring mill rather than a milling 
machine, its principal characteristic being a massive cabinet 
bed for the support of the table. A strongly braced upright 
at the left of the frame carries a slide on which is mounted 
the mandrel for the work. This slide can be adjusted verti¬ 
cally by an elevating screw resting on ball bearings. A 
graduated dial gives the adjustments in thousandths of an 
inch. The large index wheel at the rear end of the spindle 
is automatic in its action, but can be disengaged at any time 
and turned by hand. At the end of the cut the return of the 
carriage, the release of the locking disk, the turn of the index 
wheel, and the re-locking, are accomplished almost instantane¬ 
ously and without shock or jar. 

This mechanism is driven by a separate belt so that the 
speed is independent of that of the cutter. 

The cutting mechanism is carried on a carriage or saddle 
having large bearing surfaces on top of the bed. The cutter 
itself is driven by worm gearing and has six changes of 
speed. As may be seen from the figure, the cutter arbor is 
supported at the outer end, as is also the work spindle. An 
abutment is provided to hold the work firmly against the 
pressure of the cutter. 

The advance feed of the carriage is effected by a screw 
driven by chain gears and clutches. This motion is entirely 
automatic, and 12 changes of feed are provided. A hand- 
wheel is provided for adjustment, but this is automatically 
disconnected when the machine is in operation. 

The travel of the carriage is controlled by a trip motion 
which throws out the feed clutch at the end of stroke and 
starts the quick-return motion. This latter is driven in¬ 
dependently of the feed so that the carriage is returned at 




GEAR CUTTING 235 

the same high speed, whether the cutter is moving fast 
or slow. 

In fact the promptness and accuracy of the automatic 
return and resetting is the most conspicuous feature of such 
machines and is a great time-saver. The chips are caught in 
the base of the machine, the oil strains into the trough around 
the base and returns to the pump. 

Some idea of the capacity of the machine for work may be 
obtained by studying the speeds provided for. The six 
changes of speed of cutter range in geometrical progression 
from 20 to 106 revolutions per minute on this particular 
machine, and the twelve changes of feed range in a similar 
way from *019 to *263 inch per revolution of cutter. It 
will readily be understood that all such machines employing 
the usual circular cutters must waste a considerable amount 
of time, since during a large fraction of the travel the cutter 
is either entering or leaving the work and is therefore not 
cutting to its full capacity. Hence the importance of a 
careful adjustment of the travel and a prompt indexing 
mechanism. 

A machine similar to the one shown in Fig. 94 and manu¬ 
factured by the same company is intended for cutting bevel 
gears up to 18 inches in diameter. This necessitates a tip¬ 
ping table like that shown in Fig. 93 and an arrangement for 
setting the cutter either side of the centre. It is of course 
understood that a bevel gear tooth shaped by a milling cutter 
can be but an approximation to the true shape. By selecting 
a cutter of the right size, setting it to the proper depth, and 
milling but one side at a time, the approximation can be made 
reasonably close in small gears, but large gears should not be 
cut in this way. Fig. 95 illustrates another machine of the 
same general type as that shown in the preceding figure but 
one which differs considerably in detail. 

This machine is manufactured in seven sizes, cutting gears 
up to 103 inches in diameter and 20 inches face. The par¬ 
ticular machine shown has a capacity of 64 by 20 inches by 




236 MODERN AMERICAN MACHINE TOOLS 


pitch, and is intended more particularly for work on steel 
gears. 

The headstock in this machine is particularly massive, 
and is symmetrical with the bed, affording double support to 
the slide which carries the work spindle. The face plate and 



Fig. 95. 

AUTOMATIC GEAR CUTTING MACHINE. 

Messrs. Gould and Eberhardt, Newark, N.J. 


dogs for holding the work will ensure rigidity and greater 
accuracy in indexing for large gears. On the 103-inch 
machines an automatic clamp is provided in front of the 
woik, which grips the gear blank firmly while the cutter is 
engaged, and is released by a trip motion for indexing. The 
outer support for the spindle is a box-casting of considerable 
rigidity, and is adjustable by a rack and pinion. Adjustable 










GEAR CUTTING 


237 


stops under the sliding head hold the blank firmly against 
the pressure of the cut. The cutter arbor has long bearings 
at each end, and the carriage has long slides gibbed to 
prevent springing. The action of the machine is automatic, 
the carriage being fed forward slowly and returned rapidly 
by means of a screw and a system of clutches operated by a 
trip motion. The automatic feed can be disconnected at any 
time, and the carriage fed by the hand-wheel at the extreme 
right. The indexing is not as rapid as on some smaller 
machines, but probably as much so as is consistent with good 
work when such heavy blanks are to be handled. 

130. Gear-Shaping Machines. 

All the machines so far described have used the milling 
cutter for a tool, and have depended on the accuracy of the 
cutter to ensure the correct shape of tooth. If the cutter is 
properly made and properly ground, the results may be 
entirely satisfactory, but the burden is thrown entirely upon 
the manufacturer of the cutter. The problem of shaping, 
hardening, and grinding such a cutter is a serious one, and 
will be further discussed under the head of cutter grinders. 

Furthermore, any one cutter is correct only for one pitch 
and one number of teeth. Practically it is necessary to use 
one cutter for several different numbers on account of the 
expense, but this is an approximation. For instance, one 
well-known firm of manufacturers offers eight cutters for 
cutting all the involute teeth of one pitch, from 12 teeth 
to a rack. Four additional cutters are special, and can be 
had by ordering. For epicycloidal teeth, 24 cutters con¬ 
stitute a set. This method is probably accurate enough 
for ordinary work, but it is an approximation. Several 
machines have been built and put in operation at different 
times for overcoming this difficulty, and have been more or 
less successful. The same idea has been in all—to use some 
simple and easily duplicated form of cutter which shall cut, 







Fig. 96. 

24-INCH GEAR SHAPER. 


The Fellows Gear Simper Co., Springfield, Vermont 




GEAR, CUTTING 239 

or rather generate, automatically all the teeth of a set of 
wheels of the same pitch. 

The straight outlines of an involute rack tooth have 
naturally suggested the use of this as the base of the system. 
One inventor has used a cutter similar to the hob of a worm- 
wheel, but modified to suit the conditions for spur gears. 
The machine illustrated in Fig. 96 belongs to the class of 
gear-shaping machines and is in successful use at the present 
time. In brief, this machine uses a cutter of the shape of an 
involute pinion which reciprocates on a line parallel to its 
axis to cut the teeth. At the same time, the cutter and the 
gear blank are given by suitable gearing a relative rolling 
motion, the same as if gearing together. The pinion is thus 
used to shape conjugate teeth for all wheels of the set, and 
one cutter suffices for all teeth of the same pitch. 

The cutter itself consists of a thin steel disk with involute 
teeth of the desired pitch backed off so as to form cutting 
edges. The teeth can be sharpened by grinding the front 
face without changing the shape. 

The involute curves of the teeth are generated by rolling 
the cutter past a flat emery wheel with the motion that a 
pinion has relative to a rack. The flat surface of the wheel 
set at the proper angle represents the rack tooth and 
generates automatically the corresponding involute of the 
cutter tooth. In duplicating cutters by this method, it is 
only necessary to preserve a truly plane surface on the 
grinding wheel, and the machine takes care of the rest. The 
cutter, when properly hardened and ground, is placed in the 
machine and given a reciprocating motion along its axis. It 
is then fed against the work until the proper depth is 
obtained, when gear blank and cutter begin to revolve to¬ 
gether just as if in mesh, the correct relative motion being 
produced by a train of gears. Fig. 97 shows the nature of 
the motion and the successive cuts made by one tooth of the 
cutter. 

An examination of this figure shows that the shavings 





240 MODERN AMERICAN MACHINE TOOLS 


removed would all have a thin edge next to the tooth being cut, 
which should produce a nicely finished surface. The stroke 
of the cutter can be adjusted so as to just clear the blank and 
thus eliminate the lost motion inherent with rotary cutters. 
It will be seen that this is not a milling machine, but a shaper 
using a cutter of peculiar form and path. As may be seen 
by reference to Fig. 96, the machine is of the vertical type, 
having a cabinet base. This base supports the headstock 



ACTION OF CUTTER OF GEAR SHAPER. 

for the cutter spindle and the carriage for the work. The 
cutter spindle has two motions, one vertical produced by a 
crank and pitman, the other a rotation due to a train of gears 
connecting it with the work spindle. The downward stroke 
of the spindle is counterbalanced by the spring shown at the 
top. It is intended that the machine shall cut on the up or 
draw stroke, but by reversing the position of the crank pin 
a downward cut can be obtained. 

The work spindle carries an arbor, upon which several 
gear blanks may be clamped at once. The carriage can then 






GEAR CUTTING 


241 


be traversed on the horizontal ways to bring the blanks the 
right distance from the cutter, a gauge being furnished for 
setting them. There is a separate adjustment for depth of 
cut controlled by a graduated wheel. This wheel shows on 
its rim the settings for any desired pitch, and can be used 
when cutting a number of wheels of the same size, without 
disturbing the position of the carriage on the ways. The 
stroke of the cutter is adjusted by means of a slotted crank 
which drives the pitman. During the cut the work is 
supported by a stop or abutment near the cutter. A support 
is also supplied for the top end of the work arbor. 

In starting the machine, both the depth and the rotary 
feeds are put in operation. The cutter then feeds automa¬ 
tically towards the work, until a proper depth has been 
reached, when the depth feed is automatically thrown out 
and both cutter and wheel begin to rotate slowly at the 
correct relative speed. This action continues until the blank 
has made one rotation, when action ceases automatically. 
The advantages claimed by the makers of this type of gear 
cutter are in brief: 1. That one cutter will generate all the 
teeth of one pitch. 2. That the cutter can be duplicated 
accurately by grinding on a plane surface. 3. That there is 
no waste motion in the stroke. 4. That the cutter will work 
on internal gears and in narrow recesses, where it would be 
difficult to operate the ordinary cutter. It is also claimed 
that more gears can be cut in the same time than by the 
usual method. The writer knows of no published data on 
this point. There is, however, no doubt as to the correctness 
of the process, and it may be regarded as a very ingenious 
solution of the problem. Internal gears may be cut after a 
fashion on the ordinary type of gear machine, by hanging 
the rotating cutter on a projecting arm containing a train 
of gears, but the device is rather awkward and unsteady in 
appearance. If a machine, like the one just described, should 
bring about a more general use of annular gears, it would 
make a valuable improvement in machine design. 







242 


MODERN AMERICAN MACHINE TOOLS 




131. Gear-Planing Machines. 

The tooth of a spur gear is cylindrical, and the profile is 
the same from end to end, while the tooth of a bevel geai 
is conical, and the profile continually changes. Any process 





Fig. 98. jl a 

I 

24-INCH BEVEL GEAR PLANER. 


Gleason Works, Rochester, N. Y. 


of cutting, therefore, which involves a parallel cut of sensible 
breadth, either by milling or shaping, is incorrect for bevel 
gears. As has already been noticed, it is practicable to cut 
small gears with narrow faces on the ordinary machine 
without serious error. Any attempt to use this method on 


1 













GEAR CUTTING 


243 


is' 

ir 

is 


| 


I 

I 


e 

t 

3 

. 

1 




large gears, or those having faces of considerable width, 
results in gearing so imperfect as to cause trouble in running. 

The elements of bevel gear teeth are straight lines con¬ 
verging to the point where the gear shafts intersect. The 
most correct approximation to their shape is therefore 
obtained by using narrow cuts of a planing tool converging 
to the same point. The tool is to be guided by a template 
or other device, and the accuracy of the work will depend 
on the accuracy of this template and the fineness of the feed. 

This principle is old, and has often been employed in such 
machines in one form or another. 

Fig. 98 represents a gear-planing machine constructed on 
this principle, and adapted for gears up to 24 inches in 
diameter, and any bevel. The gear blank is mounted on a 
horizontal spindle as may be seen in the figure, and the took 
travels approximately in a horizontal line along a radial arm. 
This arm can be swung to any angle in the horizontal plane 
to accommodate different bevels, and being hinged at the 
centre, it has also a limited vertical movement. At the 
outer end of the arm is a roll bearing on a steel former, 
having an outline similar to that of the tooth in a magnified 
degree. As the arm swings horizontally to feed the tool into 
the work, the roll travels on the former, ensuring the correct 
outline for the tooth. Three formers are shown attached to 
a revolving plate so that any one may be brought into 
position. There is a former for each side of tooth, and a 
straight one for the roughing or gashing cut. The formers 
are produced by a machine which generates the correct 
curve, so that they may be relied upon to give exact results. 
Involute formers are furnished with the machine, but 
epicycloidal ones can be made to order. The tool slide is 
driven positively by gears, and has the Whitworth quick 
return. The machine is automatic as to return of tool and 
indexing, the same as a spur-gear machine. 

Similar machines are made for planing spur gears of a 
pitch too coarse to be economically milled. These machines 








244 MODERN AMERICAN MACHINE TOOLS 


are especially adapted for planing teeth which have been 
roughly cast to shape, a method which is sometimes more 
economical than cutting from the solid. Internal spur gears 
can be cut in the same way by employing a special tool- 

holder. Machines are built 
for planing spur gears up to 
20 feet in diameter, and for 
bevel gears up to 8 feet in 
diameter. 

A smaller machine, in¬ 
tended for cutting gears up 
to 15 inches in diameter, 
works on a different principle. 
The tool cuts with the side 
instead of the point, thus 
producing a smoother surface. 
A peculiar rolling motion is 
given to the tool, which may , 
be understood 
to Fig. 99. 

The slide which carries : 
the tool has a reciprocating 
motion in a line through the apex of the gear cone, as in 
the machines just described, and the arm is advanced to 
feed the tool into the work. Instead, however, of being 
guided by a former, as in Fig. 98, the tool-holder is turned 
through a certain angle, so that the tool, as it advances into | 
the work, rolls on the tooth, and is always tangent to the 
true curve. The motion is controlled by a cam at the outer 
end of arm, this cam being actuated by the advancing motion 
of the arm. By an ingenious reversing device, the same cam 
is made to serve for either side of tooth. Three tools are used, 
one for gashing the blank, and one for each side of tooth. 
Box tools are used on all these machines, and after having- 
been once adjusted, can be removed for grinding without 
readjustment. 


by reference 



Fig. 99. 

Detail of Cutter Arm, Gleason Planer. 






















GEAR CUTTING 


245 




132. Thread-Milling Machines. 

Formerly, all screw threads were cut by dies, or on the 
engine lathe. For ordinary bolt and screw work, the die 
machine still holds its own, but it is manifestly not suitable 
lor lead and feed screws, where great accuracy is desired. 
The engine lathe does this latter class of work well, but at 
a great sacrifice of time and patience. The thread milling- 
machine, although comparatively a new tool, has already 
demonstrated its right to be considered the most economical 
machine for the production of accurate screw threads of all 
descriptions, including those on spiral gearing. Fig. 100 
gives a rear view of one such machine adapted for milling 
work up to 6 inches in diameter and 14 inches long. A 
similar machine is built with a longer bed for screws up to 
80 inches in length. 

The cabinet base, the pan, and the bed for the support of 
the working parts are about the same as for the ordinary 
turret lathe or screw machine. 

The headstock carries a compound or double spit]die con¬ 
sisting of an outer sleeve running in bearings, and driven by 
gearing and an inner spindle carrying the collet for holding 
the work. 

There is a ratchet and pawl connection between the two 
which can be so set as to automatically turn the blank into 
the right position when multiple threads or spiral teeth are 
to be cut. 

During the return the machine is driven directly at quick 
speed by the grooved pulley on the spindle. When cutting, 
the machine is driven by gearing from the grooved cone 
pulley on the rear of the headstock, and the spindle pulley 
runs loose. The lead screw which moves the carriage may 
be seen just above the ways, and is geared to the spindle at 
the right end. In cutting fine threads the spindle is driven 
by the cone pulley, and in turn drives the lead screw. When 








246 


MODERN AMERICAN MACHINE TOOLS 


screws of steep pitch or spiral gears are to be cut, the gearing , 
is changed so that the lead screw is driven directly by the 
cone pulley, since the greater power is needed on the traverse 
motion. 



Fig. 100. 

6-INCH x 14-INCH THREAD MILLER—REAR VIEW. 


The Pratt and Whitney Co., Hartford, Conn. 


By using grooved cone pulleys and a round belt it is 
possible to belt from one step on the upper pulley to either 
of two steps below, and vice versa. Thus there are sixteen 
changes of speed on the cones, and this is multiplied to sixty- 











GEAR CUTTING 


247 


four by the arrangement of countershafting. It will be 
noticed that the cutter is driven by independent belting, 
which makes it possible to use very light belting on the 
spindle drive. The tailstock needs no special description. 
Ihe carriage is moved on flat ways and is so gibbed under¬ 
neath as to prevent any tipping or lifting action. The 
carriage is driven by the lead screw, and the feed is con¬ 
trolled by a lever in front of the headstock and not shown 
in the fi gure. When this lever is moved in one direction the 
cutting feed is started. When the lever is reversed the 
carriage returns rapidly to beginning of cut. A trip motion 
at the front of the machine operated by a dog on the carriage 
automatically reverses the machine at the end of cut. The 
feed and trip motions can be adjusted for either right or left 
hand threads. 

The milling cutter is mounted on the carriage in such a 
way that it may be tipped to right or left to correspond to the 
obliquity of the thread. This tipping is about a horizontal 
axis through the cutting point of the tool, so that the point 
remains always on a level with the axis of the work. 

The cutter is driven independently of the rest of the 
machine through gears on the same axis with the trunnions 
to allow for the tipping. 

The driving pulley is turned by six round belts running 
in six grooves and coming from a drum above. This arrange¬ 
ment gives the necessary flexibility, and at the same time 
does away with the danger to cutter and to work which would 
result from the breaking of a single flat belt. 

An adjustment of the carriage on the lead screw is effected 
by turning the lead-screw nut. When this latter is locked 
by turning a lever the carriage can be moved by the lead 
screw alone. 

This size of machine is equipped for cutting fine threads 
on screws f inch in diameter, and from that up to the 
teeth of 6-inch spiral gears. Cutters are provided with 
staggered teeth cutting alternately on either side, and a 




248 


MODERN AMERICAN MACHINE TOOLS 


special automatic grinding machine makes it possible to dupli¬ 
cate these with precision. Perhaps no one class of machine 
tools has done more to advance the cause of precision in iron 
and steel cutting than the gear and thread cutters. Gears 
and screws are used on nearly all machine tools, and if 
inaccurate will perpetuate their failings according to an 
unalterable law of heredity. The lathe with a poor lead 
screw will always make poor screws. The milling machine 
with inaccurate gearing will always make inaccurate gears. 

So, whether the manufacturer buys his gears and lead 
screws of the specialist, or whether he makes them in his 
own shop, the product of the modern gear cutter and thread 
cutter is bound to make itself felt as a promoter of accuracy 
in manufacture. 








CHAPTER IX 


GRINDING MACHINERY 

133. Grinding in General. 

One of the marked improvements in machine manufacture 
during the past ten or fifteen years has been the increase 
of grinding processes as a means of finishing metal parts. 
Formerly the grinding wheel was regarded as an agent for 
coarse rough work, and as an ally rather of the foundry and 
the forge shop than of the machine shop. 

Improvements in the material and make-up of grinding 
wheels and corresponding improvements in the machines for 
operating them have made it possible to use them for the 
most accurate and exacting work. Add to this fact the 
possibility of finishing chilled and hardened surfaces which 
could not be cut by steel tools, and you have sufficient reason 
for the change. 

The fact that a piece is finished by grinding does not 
necessarily prove that it is more nearly correct than a similar 
piece finished in the ordinary way. At the same time it is 
practicable to finish with the wheel, if properly used, in such 
a manner as to equal, if not surpass, any other treatment, 
and at a less cost. 


134. Classification. 

The ordinary emery or corundum wheel mounted on a 
plain stand, and used for the rough work of the shop, need 

249 




250 MODERN AMERICAN MACHINE TOOLS 

not be specially considered, as it is hardly a machine. 
Finishing and special grinders may be classified as follows :— 

(1) Surface-grinding machines. 

(2) Cylindrical grinding machines. 

(3) Universal grinding machines. 

(4) Tool grinders. 

(5) Twist-drill grinders. 

(6) Cutter and reamer grinders. 






135. Surface Grinding. 

By surface grinding is here meant the production of plane 
surfaces only. This may be accomplished in several different 
ways, by the use of cylindrical wheels cutting on the peri¬ 
phery, by ring wheels cutting on the annular face, or by flat 
discs covered with abrasive material. When the cylindrical 
wheel is used, the plane surface must be obtained by the 
traverse of the wheel or of the work, in two directions, as in 
Fig. 103. With the ring wheel, such as shown in Fig. 102, 
dependence can be placed on the face of the wheel for secur 
ing a plane surface just as in the rotary planer, and the table 
is fed longitudinally. When the flat disc made of steel is 
employed as in Fig. 101, the disc itself is supposed to give 
the necessary plane surface, and the table is merely used to 
guide the work. 

Surface grinders are not generally used to remove large 
quantities of metal from castings or forgings, since this can 
be more economically done by the planer or the milling 
machine. When, however, it is possible to cast or forge 
quite near to the finished size, as in small machine parts, the 
grinding machine can be profitably used for removing a thin 
layer of metal. Unlike planing or milling machines, the 
grinding machine does not need to get below the scale 
in order to work satisfactorily, and can finish by removing 
^ as well as by removing ^ of an inch of metal. 

Grinding machines which have automatic tables 


as m 









251 


GRINDING MACHINERY 

Pigs. 102 and 103 are profitably used for finishing to size 
pieces which have already been roughed out on the planer. 
Any degree of smoothness or polish can be given in this way 
by using the proper grade of wheel and the tool marks com- 



Fig. 101 . 

UNIVERSAL DISC GRINDER. 

Diamond Machine Co., Providence, R.I. 


pletely effaced. Perhaps the most important field of the 
grinding machine, and one which is peculiarly its own, is the 
surfacing of machine parts made of chilled iron, of hardened 
steel, or of any alloy which is too hard to be cut in the 
ordinary way. 












252 


MODERN AMERICAN MACHINE TOOLS 


136. Disc Machines. 

Disc machines, such as the one shown in Fig. 101, are 
intended more for use in finishing small pieces which can be 
held by hand or at least adjusted by a hand feed. 

The Gardner disc grinder differs from others in its class 
in having a spiral groove on the face of the steel disc. This 
groove assists in the holding of the glue by which the emery 
cloth or paper is secured to the disc, and also gives the emery 
a corrugated surface, which ensures more rapid cutting. The 
discs on this machine are of open-hearth steel, about 18 inches 
in diameter and T 7 g inch thick. The spiral groove is ^ 
inch wide and ^ inch deep, 5 grooves per inch of radius. 
A wheel of this size can be safely run at 1800 revolutions per 
minute, or over 50 per cent, faster than the safe speed of a 
solid emery wheel of the same diameter. 

The table is a swinging one, counterweighted and adjust¬ 
able at different angles with the face of the disc. 

The machine is sometimes driven directly by an electric 
motor, the starting box being in the base or cabinet. The 
high speeds at which grinding machines are run makes the 
use of electric driving much more simple than for ordinary 
machine tools. 

In Fig. 101 may be seen a disc machine of a different 
type. The discs are of steel, but are plane, and a special 
cement is used in securing the cloth or paper. This machine 
differs from the machine just described in the construction 
and operation of the tables. The upright carrying the table 
has a swinging motion on a stud or shaft projecting from the 
base of the machine, but may be clamped in any desired 
position. The upright has a vertical adjustment, and as it is 
raised or lowered it automatically adjusts the counterweight 
by means of a chain and pulley, so as to keep the table in 
equilibrium. The table may be moved to and from the disc 
by the micrometer wheel shown, and an adjustable stop is 
provided to regulate the depth of cut. 


GRIND TNG MACHINERY 


253 


The quadrant for tipping the table is shown at the left of 
the machine. This is graduated to show the exact angle of 
inclination. On the top of each table is a protractor swinging 
in the plane of the table about the centre of the disc and 
read by graduations on the rim of the table. It is possible 
with this table to set the work at any desired angle in the 
vertical or the horizontal plane, and by the use of the feed 
screw and micrometer to cut to any desired size or depth. 

The machine runs at 1800 revolutions per minute, and 
according to the statement of the makers is capable under 
favourable conditions of removing from 4 to 6 cubic inches 
of tool steel in an hour from the end of a bar one inch 
square without renewing emery paper. 


137. Ring Wheels. 

When wheels of emery or other powder bonded together 
with adhesive material are to be employed, the flat disc 
becomes impracticable, and a cup wheel or ring wheel is used. 
Such a wheel cuts with the comparatively narrow face of 
the ring and gives a true surface. Even if this face becomes 
worn a traverse motion of the work in the plane of rotation 
will develop a plane surface just as in rotary planing or end 
milling. Fig. 102 shows a ring-wheel grinding machine with 
automatic table and adjustable head. The wheel itself is in 
the shape of a hollow cylinder and is held in a concentric 
chuck of cast iron. The wheel is backed up by a circular 
flange nut which can be adjusted as the face of the wheel 
wears off. The clamping is effected by a taper ring outside 
the wheel held by a series of bolts. The wheel is thus guarded 
against bursting, a danger to which ring wheels are peculiarly 
liable, and at the same time can be adjusted for wear until 
completely worn out. 

The wheel spindle is carried in a sliding head which can 
be raised or lowered on the upright to accommodate different 
sizes of work. The head and upright are moved to and from 





RING WHEEL GRINDER. 








































GRINDING MACHINERY 


2 C CT 

00 

the table by a feed mechanism operating automatically at 
each traverse of the work. The feed can be regulated from 
0 to | inch per stroke. The table or platen is similar to 
that of a planer and reciprocates on ways cast to the bed. 
Dogs on the table regulate the stroke and reverse it automati¬ 
cally. The control of both table traverse and wheel feed 
is secured by hand-wheels at the front of the machine con¬ 
veniently located for the operator. Such machines are built 
in lengths ranging from 50 to 180 inches. The machine shown 
in Fig. 102 will take work 80 inches long, 22 inches wide, and 
12 inches high. 

138. Machines with Cylindrical Wheels. 

The grinding machine which is most universal in its 
application is probably the one employing a cylindrical wheel 
cutting either on the rim or on the face. Fig. 103 illustrates 
such a machine built in a form similar to that of the open- 
side planer. 

The grinding wheel is carried on a spindle having an 
outer support, carried by an overhanging arm as in the 
milling machine. An especially long box also affords support 
to the spindle. The spindle or arbor is mounted on a sliding 
head, which in turn is clamped to the housing or upright of 
the machine and can be raised or lowered by means of 
elevating screws. The sliding head can also be swivelled 
by loosening the nuts in the centre, so as to tip the wheel 
slightly in facing down vertical surfaces. To accommodate 
the various adjustments of the head, the belt from the 
countershaft is led over idle pulleys which can be shifted 
to keep the proper tension. The upright is broad and has 
large bearing surfaces, both for the sliding head and for its 
own contact with the bed. It is gibbed to the ways on the 
bed to ensure rigidity, and is fed by a screw to or from the 
table at each traverse of the latter, thus making it possible 
to cover the entire surface automatically. This feed motion 







256 MODERN AMERICAN MACHINE TOOLS 

can be varied from 0 to g- inch for each traverse. As is 
shown in the cut, the table travels on flat ways to which it 
is gibbed, and is driven by rack and gears. If it is desired 
to do wet grinding, the water is drained from the table and 



Fig. 103. 

OPEN SIDE SURFACE GRINDER. 

The Safety Emery Wheel Co., Springfield, Ohio. 


carried to a tank in the base of the machine. The table is 
controlled by a friction clutch so that it may be stopped at 
any time and operated by hand. 

The wheels used on these machines are provided with 




























GRINDING MACHINERY 


257 


safety collars, which grip shallow hubs on the faces of' the 
wheels and safeguard them against rupture. With these 
collars it is deemed safe to run the wheel at surface speeds of 
G000 to 6500 feet per minute. 

The various hand-wheels for adjusting and controlling the 
machine are located within reach of the operator at the front. 
A small surface grinder (made by the Walker Company of 
Worcester, Mass.) is directly driven by an electric motor on 
the spindle. The machine is also furnished with a magnetic 
clutch built into the platen for holding small pieces of work. 
The chuck is magnetised or demagnetised by the starting and 
stopping of the machine and requires no special attention. 

The necessary vertical adjustment is in the head carry¬ 
ing the wheel and is fitted with a micrometer. The platen 
reciprocates on a carriage or saddle which moves transversely 
for the cross feed. Both of these motions a,re controlled by 
a motor in the base of the machine. The platen can be 
operated automatically without the cross feed, or both can be 
run at once. Variable speed for the platen is secured by the 
electric drive, and electric lamp and alarm bells complete 
the outfit. This machine is interesting as an example of 
what may be done in the way of electric driving and control. 

The fact that the entire machine is driven by one electric 
wire makes it possible to move the machine from place to 
place. It is accordingly fitted with wheels to facilitate its 
being transported. 


139. Cylindrical Grinding Machines. 


Grinders which are used for producing cylindrical and 
conical surfaces are classified as plain and universal, much the 
same as are milling machines. 

The plain machine is capable of grinding straight or taper 
shafts up to a certain limit, but cannot be used for the variety 
of work done on the universal machine. Like its cousin, the 
plain milling machine, the plain grinder is simpler, has less 

R 








MODEL SHOWING METHOD OF TURNING FOR GRINDING. 









GRINDING MACHINERY 259 

i joints and adjustments, and is the better machine for plain 
work. 

As has been already said in discussing surface grinders, 
it does not usually pay to remove large quantities of soft 
metal by grinding. The part to be finished had better be 
roughed off in the lathe, as illustrated in Fig. 104, to within 

or 3 ^ inch of size, and then finished by grinding. As 
shown in the figure, it is not necessary to take a finishing 
cut in the lathe, but merely to reduce the piece to somewhere 
near the desired size in as rapid a manner as possible. Where 
machine parts are to be hardened and then ground, a closer 
finish in the lathe is necessary, leaving only a few thousandths 
to be removed by grinding. A plain grinding machine must 
have the following motions or adjustments in order to do the 
work :—( 1 ) A rapid rotation of the wheel usually at a surface 
speed of from 5000 to G 000 feet per minute; ( 2 ) a slow 
rotation of the work, about the same as in a lathe, from 25 
to 75 feet per minute ; (3) a traverse of either wheel or work 
longitudinally at the rate of from one-quarter to three- 
quarters the width of emery-wheel face for each revolution 
of the work; (4) a cross feed or adjustment for setting the 
wheel to give the proper diameter of work ; (5) a swivelling 
of the table carrying the work to produce taper cuts. Some 
manufacturers prefer to move the wheel and some to move 
the work in getting the necessary traverse. 

Fig. 105 shows a rear view of a machine where the work¬ 
table moves longitudinally and the wheel head remains 
'stationary. The rear view was chosen to show more clearly 
the driving mechanism. 

The head carrying the wheel arbor is massive in construc¬ 
tion, so that its own weight keeps it down on the ways. 
The head slides to and from the work to regulate the depth 
of cut, having one fiat and one large Y-shaped way. This 
motion is, of course, regulated from the front of the machine 
with a micrometer. The machine shown in Fig. 105 may be 
driven by a constant-speed motor. The countershaft which 






260 MODERN AMERICAN MACHINE TOOLS 


drives the wheel is hung in a hinged frame, and this can be 
adjusted to tighten the belt running to the wheel arbor. 
The motor drives the countershaft through a belt which is I 
tightened by an idle pulley and weight, thus maintaining aj 
constant belt tension as the head is moved in or out. The! 
overhead countershaft for turning the work is driven from j 
the same motor. The belt to the work cone runs at the 



Fig. 105. 

PLAIN GRINDING MACHINE—REAR VIEW. 


The Norton Emery Wheel Co., Worcester, Mass. 

[I 

top on a long drum to allow for the traverse of the table.; 
As thus arranged the machine is self-contained and indepen¬ 
dent of any overhead connections. Such a drive leaves the! 
way clear for a travelling crane above. 

The work turns on dead centres and is steadied by 
numerous back rests arranged at intervals. The entire table j 
carrying head and foot stocks and back rests is traversed 
automatically by the wheel, the latter always remaining in 



























261 


GRINDING MACHINERY 

i the same position except as it is fed in to grind the proper 
size. 

The makers claim that by this arrangement they secure 
greater steadiness and accuracy. It certainly has the 
advantage of keeping the cutting surface always in front 
of the operator as he stands at the centre of the machine. 
Provision is made on this, as on all similar machines, for 
grinding tapers by swivelling the top of the table so that the 
line of centres stands at an angle with the ways. This is 

VARiaBjlT TENSION SPBlNfl TO Ta ICE l/P 



GRINDING TWO TAPERS. 

The landis'Tool Co., Waynesboro', Pa. 


the only swivelling possible with the plain machine, and it 
is this limitation which distinguishes it from the universal 
machine. 

Both the traverse of the table and the cross feed of the 
wheel carriage can be made automatic. Either the speed of 
rotation of the work or the feed of the table can be varied 
independently without affecting the other. All the wheels 
and levers for controlling the machine are located in front 
near the centre of the machine. These grinding machines 
are made in sizes from 10 x 50 inches up to 18 x 168 inches, 
and arranged for either belt or electric drives. 

















































262 MODERN AMERICAN MACHINE TOOLS 


140. Universal Grinding Machines. 

Two views of a universal machine are given in Figs. 106 
and 107 showing some of the details of the machine. While 
this particular make of machine has a stationary work table 
and a travelling wheel carriage, it is a peculiarity of the 
make and not of the type, and the plain machines made by 
the same firm have the same arrangement. 

Perhaps the top view shown in Fig. 106 illustrates best 
the ‘ universality ’ of the grinder. The bearings of the 
grinding wheel are carried on a sort of compound rest- 
having a swivelled connection to the carriage beneath. By 
means of a small micrometer wheel, shown in the illustration, 
motion can be given in the direction of the upper slide, either 
at right angles to the line of centres of the machine, or at 
any angle to which the slide may be swivelled. The milled 
screw head on one end of the wheel spindle can be used for 
giving an endwise adjustment to the wheel for face grinding, 
and is also graduated as a micrometer. This adjustable head 
for the wheel spindle is mounted upon a long and wide 
carriage that completely covers the ways on which it slides 
and protects them from dust and grit. The speed of traverse 
depends upon the width of wheel used, and is usually from 
one-half to three-fourths that width for each revolution of 
the work. 

The head and tail stocks are located on a swivelling table, 
which can be seen in Fig. 106 as turned for grinding tapers. 
This table is graduated on the curved ends for degrees and 
for inches of taper per foot, and has a fine adjusting screw 
for precise measurements. The combination of the swivel on 
the wheel head and that on the table makes it possible to 
do work like that shown in the figure, where two tapers 
are being ground with one setting of the machine. Both 
head and tail stocks are bolted to a flat way on the table, 
and the lathe is protected from water and emery grit by 



GRINDING MACHINERY 263 



adjustable guards. As shown in Fig. 107, the headstock 
has a swivelling base to allow of grinding bevels and tapers 
in the chuck, and at 
greater angles than 
allowed by the table 
swivel. When used 
for grinding shafts on 
the dead centres the 
head is held exactly 
in line by a cotter 
pin, and the belt 
drives a loose pulley 
on the end of the 
spindle with a dog 
for turning the work, 
the spindle and the 
centre remaining stationary. When grinding work in the 
chuck, as shown in Fig. 107, the belt drives a pulley next 
to the head, which pulley is keyed to the spindle. 

In this machine both wheel and work are driven from 


Fig. 107. 

Grinding Taper in Chuck. 

'The Landis Tool Co., Waynesboro’, Pa. 


drums on the countershaft to allow for the necessary traverse 
motion. Stepped cones on the various countershafts make 
it possible to vary the relative speed of wheel, work, and feed 
motions to suit different materials and sizes. 

The universal machine, while capable of doing the ordinary 
straight and taper work on spindles and shafts, is particularly 
adapted for finishing tools and other pieces having com¬ 
plicated shapes. A special attachment is provided for inside 
grinding, a small wheel being used at the end of a rather 
slender arbor. Such grinding, like internal milling, must be 
regarded as a necessary evil, and it is not expected that it 
can be done as rapidly or as satisfactorily as outside work. 

Another universal machine is illustrated in Fig. 108. In 
general design this is similar to the machine shown in 
Fig. 105, since the wheel stand is stationary while the 
grinding is being done and the work table travels on ways. 































CO 

I—I 

o 

CD 

X 

CO 

£ 

HH 

Ol 


£ 


w 

qo O 


s o 


P5 

o 

<! 

GO 

PS 

W 

> 

t-H 

£ 



The Brown and Sharpe Manufacturing Co., Providence, R 























GRINDING MACHINERY 


265 


Dogs on the table trip the reversing lever shown in front and 
can be adjusted for any stroke. The table swivels on its 
centre to any angle up to five degrees each way. The head- 
stock swivels to any angle. The wheel stand swivels and 
has two motions besides—a transverse adjustment which can 
be set to thousandths of an inch, and the automatic cross-feed 
which operates at each reversal of the table. The latter can 
be adjusted so as to give from *00025 to '004 inch at each 
stroke. The machine can be arranged for either wet or dry 
grinding. 

All grinding machines must possess three principal quali¬ 
fications in order to be successful—viz. accuracy and freedom 
from lost motion in the guides; provision for thorough 
lubrication of all bearings; protection of all bearings from 
dust and grit, or from water, as the case may be. It 
may be assumed that these conditions have been met in the 
machines described in this chapter. 


141. Tool Grinders. 

One of the most common uses to which the grinding 
machine is put in the machine shop is that of grinding lathe 
and planer tools, and perhaps any grinding machine could be 
better spared than the one which performs this humble task. 
For such purposes the grinder has almost entirely superseded 
the grindstone, the latter being only used for thin-edged 
tools like those employed in the pattern shop. 

In order to obtain the best results with lathe and planer 
tools, it is necessary that they should be sharp, and that they 
should be of the shape best adapted to the work to be done. 
These results are most readily obtained by having one man 
do all the grinding, both of new and old tools. Naturally 
the machine would be located in the tool-room, and the 
tools would be checked out to the men the same as other 
tools. This method also prevents the common practice of 
allowing high-priced men to waste their time in grinding 










266 MODERN AMERICAN MACHINE TOOLS 


tools or in waiting for others to grind. There is no good I 
reason why the machinist should sharpen his own lathe or 
planer tool, when reamers, milling cutters, etc., are sharpened 
in the tool-room. According to this system, when a workman 
finds that his tool is dull he immediately returns it to the 
tool-room and receives another which is sharp and of the 
same shape as the first. 

It is equally important that the tool-grinding machine 
should be such as will readily duplicate the proper angles 
and shapes of the various tools, and that patterns should be 
kept in stock to preserve the record of shapes. 

Fig. 109 illustrates a tool-grinding machine intended 
especially for tool-room use. The necessary patterns and 
data for grinding are sent with the machine. The grinding 
wheel has two cutting faces, conical in shape and making 
an angle of 90 degrees with each other. This shape gives 
more grinding surface, and is more convenient for grinding 
tools of various bevels, as well as for fine work in corners. ! 
As is well known, a plane surface is not suitable for grinding 
tools, since it readily glazes and overheats the tool. The 
wheel spindle has unusually long bearings, which are well 
protected from water and grit. A small crane is provided 
for convenience in handling the wheel. The machine is 
intended for wet grinding, and an abundant supply of water 
is provided. If the machine is used on high-speed steels 
the water is omitted. 

1 he tool holder is universal, having all the motions neces¬ 
sary for the grinding of any tool for lathe, planer, or slotter, 
internal or external. The tool is aligned and clamped by 
the base as it would be in the lathe or planer. The holder 
or chuck can be rotated around a horizontal axis parallel 
with the shank of the tool and set to within a tenth of a 
degree. The frame holding the chuck can in a similar 
manner be rotated about a vertical axis passing near the 
point of the tool. I he frame is carried on two slide rests 
90 degrees apart, or parallel to two grinding faces. Finally, 




fc? A 



William Sellers and Co., Philadelphia, Pa. 








268 MODERN AMERICAN MACHINE TOOLS 

the whole combination is carried by a vertical slide counter-1 
balanced by a spring. The tool, being properly clamped 
to the chuck and adjusted to the desired angle vertically 
and horizontally, can be then moved accurately in two 
horizontal lines and one vertical line, so as to give the neces¬ 
sary traverse for producing the surface required. Tables 
of angles accompany the machine, and enable the operator 

to reproduce any 
of the pattern 
tools. Of course 
the list sent can 
be varied or added 
to as the judg¬ 
ment of the fore¬ 
man may dictate. 

A great varietv 
of lathe tools can 
be ground on this 
machine, and the 
same rule applies 
to tools for other 
machines. Special 
chucks and holders 
are furnished, and 
others may be had 
to order. The 
machine shown in 
Fig. 109 is capable of handling stock up to 2 x 2|- inches. 
A smaller machine limited to stock 2 x 1| inches is simpler 
in construction and carries a cylindrical wheel. The larger 
machine can also be used for duplicating curved shapes by 
the employment of a form plate and guide rolls. These 
machines are also particularly useful in grinding thread tools 
of various shapes where accuracy is absolutely necessary. 

Another tool-grinding machine is made by the Gisholt 
Company, Madison, Wis., and differs in many particulars 



Fig. no, 

Gisholt Tool Holder, 






269 


GRINDING MACHINERY 

from that just described. Fig. 110 is an elevation of the 
tool holder, and shows the various adjustments. The chuck 
in the centre holds the shank of the tool bv three set screws. 
For grinding bent tools the chuck may be turned 30 degrees 
either side of the centre line to bring the face of tool parallel 
to grinding surface of wheel, the angle being shown by a 
graduated circle just below the chuck. The circular frame 
holding the chuck may be rotated about a horizontal axis 
parallel to shank of tool through an entire circle for grinding 
sides and top of tool. The circular base of tool holder may 
be turned about a vertical axis passing near point of tool 
through 320 degrees. The entire tool holder may be tipped 
about a horizontal axis through an angle of 15 degrees to 
allow for clearance on thread tools. The graduated vertical 
circle at the bottom shows this angle. With this machine, 
as with the one just described, it is possible to grind any 
face at any angle, and to duplicate pattern tools indefinitely. 

142. Twist-Drill Grinders. 

What has been said with regard to the grinding of lathe 
and planer tools in the tool room applies equally well to twist- 
drill grinding. The constant use of the twist drill on all 
kinds of work, and the fact that a drill poorly ground will 
spoil work, are two potent arguments for the use of the drill¬ 
grinding machine in every shop. 

It is practically impossible to grind a twist drill accurately 
by hand, while, in a properly designed machine, this may be 
done with ease. There are two principal requisites in twist- 
drill grinding, one that the two lips shall have the same length 
and inclination, the other that the clearance may be just 
enough for free cutting and no more. This last requirement 
can be met practically by grinding the surface of the lip in a 
cone whose axis is in a different plane from that of the drill 
as shown in Fig. 11 1. When so ground, the lip will have a 
clearance increasing slightly back of the edge and also being 


270 MODERN AMERICAN MACHINE TOOLS 


greater near the point. If, then, the drill in being ground is 
oscillated about this inclined axis, the correct shape will be 
produced. 

Either wet or dry grinders may be used; if water is 
employed it is better to have the drill ground with the point 
lower than the shank, and apply the water to drill rather 
than the wheel, to avoid spattering. This is done in the case 
of all water grinders of the type shown in Fig. 112. This 




William Sellers and Co., Philadelphia. 

figure shows a so-called universal grinding machine adapted 
to grinding all styles of drills, having two cutting lips, and 
capable of giving any desired angle to tbe lips from 75 to 140 
degrees, and any desired clearance. A ring wheel is used, 
mounted on a cast-iron face plate, and the drill is ground 
against the annular face. As the drill surface is convex 
there will be line contact and no danger of glazing. The 
drill is held by two Y-shaped rests some distance apart, so 
as to give the mean axis of drill and allow for any slight 
irregularities. An adjustable stop regulates the longitudinal 
position of drill, and a steel rest bears against the lip which 
is being ground and determines its proper position. The up 
stands in approximately a vertical position, and a raising or 


































GRINDING MACHINERY 


271 


lowering of the holder changes the lip angle without disturb¬ 
ing any of the other adjustments. The motion of the drill 
in grinding consists of a rocking about the inclined axis under 
the holder and a slight perpendicular movement. The com¬ 
bination of these two gives a helicoidal shape to the lip 
surface, similar to the surface of the cut, but having the 
lecessary clearance. The clearance can be changed by rotat- 
_ng a nut at the bottom, thereby shifting the axis. 

The hand-wheel at the side pulls the holder back from 
the wheel when a new drill is placed in position. The 
horizontal handle near this turns the holder about a hori¬ 
zontal axis and moves the drill back and forth over the face 
of the wheels. 

A calliper attachment on the holder enables the operator 
to set the machine for any size of drill. The combination of 
i movements described makes it possible to grind the correct 
surface on the lip of a drill of any size, at any desired angle 
and any clearance within reasonable limits. Other grinding 
machines by the same makers have the adjustments of the 
universal machine just described, with the exception of that 
which varies the angle between the lips, the standard included 
angle of 118 degrees having been adopted. The machines 
are arranged for electric or air drive, if desired, and can be 
had for either wet or dry grinding. 

The Yankee drill grinder differs from the one just 
described in one very important particular—viz. the angle 
between the axis of oscillation and the axis of the drill. 

In Figures 111 and 112 the angle is shown as consider¬ 
ably less than 90 degrees ; in fact, as about half that included 
between the edge of the lip and the axis of the drill. On 
the other hand, in the Yankee grinder this angle is 90 
degrees, and the axis of oscillation is beyond the plane of 
the wheel. This gives an inverted cone as the surface of the 
lip, and materially changes the ratio of the clearance angles. 
Opinions are divided as to which is the correct angle, but 
the weight of evidence seems to favour the small angle. One 

o 






272 MODERN AMERICAN MACHINE TOOLS 

large firm of twist-drill manufacturers gives as the results 
of its experiments that the best ratio of the clearances for 


Fig. 112. 

THE WORCESTER UNIVERSAL TWIST DRILL GRINDER. 

The Washburn Shops, Worcester, Mass. 

good cutting power and endurance is obtained by using the 
smaller angle, as in Fig. 112, 




. 




' 


V 


-i 
















GRINDING MACHINERY 


273 


William Sellers and Company of Philadelphia, from whose 
catalogue Fig. Ill has been reproduced, manufacture a drill 
grinder embodying the principles which have been explained 
in this chapter, and also having a drill-pointing attachment 
which grinds small grooves either side of the point, and thus 
improves the cutting edge there. Twist-drill grinders are 
frequently run by electric motors, and two systems are in 
vogue. On one the motor is on the spindle of the machine 
and direct-connected ; in the other, the motor is located in 
the base of the machine and connected with the wheel spindle 
by a belt. The disadvantage of this latter method is, of 
course, the use of the belt. The advantage is the possibility 
of running both motors and wheel at the most economical 
speed. A machine of this class with the motor at the top 
is also perhaps a trifle top-heavy. 

143. Cutter and Reamer Grinders. 

The increasing use of milling cutters, and the demand 
for standard sizes in all classes of reamers, have made grind¬ 
ing machines for this style of cutting tool almost a necessity. 

Most of the machines for this class of work are of the 
so-called universal type, as shown in Fig. 113. These machines 
will grind almost any shape of cutter, reamer, mandrel, or 
collar that it is possible to imagine. The wheel usually 
employed is of the hollow cylindrical or hollow conical type, 
which gives a narrow cutting edge and a straight clearance, 
and can be used on a large variety of shapes. 

For plain work the thin disc wheel, if of sufficiently large 
diameter, gives good results. Fig. 113 shows the head of a 
universal grinder as used for sharpening the teeth of a large 
mill. In this case a wheel is used as large as will con¬ 
veniently clear the next tooth, so as to grind a clearance 
having as little concavity as possible. The wheel cuts up on 
the tooth, and the latter is held by hand against the rest 
underneath. The various adjustments may be readily seen 

s 


























GRINDING MACHINERY 


275 


in the figure. The wheel spindle has two speeds, and is 
provided with a vertical adjustment for regulating the belt 
tension, and to make it possible to use endless belts. The 
table of the machine is carried on a knee, which can be swung 
entirely around the column and thus bring the wheel into 
any desired relation to the work. A cross-slide on this knee 
is operated by a hand crank having a micrometer attachment 
and serves to feed the work to and from the wheel. The 
table can also be raised or lowered by a rack-and-pinion 
arrangement, thus securing the necessary clearance. The 
table can be swivelled on the slide underneath, and the latter 
has a traverse movement for feeding the work, which may 
be operated either by a wheel or by a lever. In addition to all 
this, the head, which holds work not ground on centres, can be 
swivelled in both vertical and horizontal planes. All of the 
swivelling adjustments are provided with graduated circles and 
the straight ones with micrometer collars. It is possible with 
such a machine to present the work at any angle to the wheel, 
and thus to grind either flat, cylindrical, or conical surfaces. 

Some of the applications of a universal machine such as de¬ 
scribed are found in sharpening milling cutters, gear cutters, and 
reamers of every description, in grinding mandrels and spindles 
either straight or taper, and in finishing collars and gauges 
inside and out. A small grooved pulley on the work spindle 
makes it possible to grind work on dead centres when necessary. 

In a small way such a machine covers the entire field of 
surface and cylindrical grinding, and is a very useful tool in 
shops making fine machine parts. 

The emery-wheel head of the machine just described is 
a good example of this class of spindle and bearings. Both 
bearings are adjustable lor wear, are long in proportion to 
length of spindle, and are protected by dust caps. Two ends 
are provided for wheels, one end usually carrying a disc and 
the other a cup wheel. In Fig. 114 is shown another uni¬ 
versal grinder, differing widely in detail from the last. The 
table and slides of this machine are swivelled to the top of 







276 MODERN AMERICAN MACHINE TOOLS 


the column and have a bearing circle of large diameter 
graduated to degrees. A sleeve inside this circle gives a 
vertical adjustment for the wheel head, the latter being 
raised or lowered by the graduated hand-wheel at the right 
of the column. It will be seen that the working parts of the 
machine can thus be revolved around the wheel head as a 



Fig. 114. 

NO. 2 UNIVERSAL TOOL AND CUTTER GRINDER. 

The Norton Emery Wheel Co., Worcester, Mass. 


centre, to bring the work at the proper angle with the wheel. 
Above this swivel or turn-table is a cross-slide operated by 
the hand-wheel in front, which has micrometer graduations. 
The traverse of the table is above the cross-slide, and several 
feeds are provided ; a rapid hand feed controlled by the pilot 
wheel in front, a slow feed or micrometer adjustment operated 
by the small wheel at the right, and an automatic feed driven 
by gearing underneath the left end. 
















GRINDING MACHINERY 277 

Ihe upper part of the table is swivelled for grinding 



Fig. 115. 

14-INCH CUTTER AND REAMER GRINDER. 

The Beclcer-Brainard Milling Machine Co., Hyde Park, Mass. 


tapers, and various heads and vices with swivelling connec¬ 
tions are provided for grinding at various angles. 

















278 MODERN AMERICAN MACHINE TOOLS 


A four-speed countershaft accompanies each machine. 
As is usual, provision is made for revolving the work with a 
belt when grinding arbors and mandrels on dead centres. 
The next machine, Fig. 115, is intended especially for sharp¬ 
ening cutters and reamers, and is simpler in construction 
than the universal machines. The frame which supports the 
wheel spindle also carries two columns for the work carriages, 
one of the latter being intended for peripheral grinding, and 
the other for end grinding. Both carriages can be swivelled 
on the supporting columns, and both have vertical adjust¬ 
ments, cross feed and longitudinal traverse. The heads, 
carrying the centres or chucks, can be swivelled on the table 
for taper work. 

The use of separate carriages for the two kinds of grind¬ 
ing mentioned simplifies somewhat the problem of setting 
the work and does away with some special attachments. 

144. Emery Wheels. 

T1 ie shapes of wheel used on the machines described in 

this chapter vary with the nature of the work, but one 

general principle governs the selection—viz. to have a narrow 

cutting surface on the wheel, as this ensures face cutting and 

prevents glazing. The disc grinder is an apparent exception 

to this rule ; but even in these, the use of a corrugated surface 

* © 

has increased the cutting capacity. 

The shapes most used are : (l) the thin disc cutting with 
its edge ; (2) the ring wheel, cutting on the narrow annular 
face; (3) the cup wheel, of rather a saucer shape, and cutting 
on the thin edges. Emery wheels in this country are graded 
in two ways ; first, according to the fineness of the grain, and 
second, according to the hardness of the bonding material or 
the texture. 

The fineness of the grain is shown by numbers indicating 
the number of meshes per inch of the sieve or screen through 
which the grains of emery would pass. Thus, a grade-40 










GRINDING MACHINERY 


279 


wheel would be one made of emery whose grains would pass 
through a 40-mesh sieve. 

As to hardness, wheels are usually graded as medium, 
hard, soft, very soft, and very hard, the grades being denoted 
by letters. Unfortunately, different firms use different 
letters, so that it is necessary to have the firm’s list or 
catalogue, in ordering intelligently. 

One firm of wheel makers use all the letters of the 
alphabet to denote the different grades, beginning with A 
as extremely soft, and ending with Z as extremely hard. 

For use on steel cutters and small tools, the makers 
generally recommend a fine grain, medium or soft wheel. If 
the wheel is too hard it will glaze, while, if too soft, it loses 
its shape and size too rapidly. There has been considerable 
discussion of late with regard to the safe speed of emery 
wheels, and some litigation lias resulted from accidents 
occurring in service. Experiments made by the writer and 
reported in the Transactions of the American Society of 
Mechanical Engineers for the year 1903, show that emery 
wheels ranging from 10 to 60 size of grain, and of various 
degrees of hardness, are entirely safe at speeds of 5000 to 
6000 feet per minute, the bursting speed varying from 11,500 
to 19,200 feet per minute. These were disc wheels, and it is 
apparent that cup or ring wheels would need to be more 
carefully handled, and should be safeguarded by chucks or 
face plates, unless run at a lower speed. 


CHAPTER X 


PUNCHING AND SHEARING MACHINERY 

145. Pressure Machines. 

Machines which shape or cut metal by direct pressure on 
dies, belong rather to sheet-metal works, such as tank and 
boiler shops, than to the general machine shop. As it is the 
intention to limit the present treatise to a consideration of 
those machines which find a place in the general shop, only 
such machines will be illustrated or described in this chapter. 

These are naturally divided into two classes, punching 
machines and shearing machines. The two functions are 
much the same, require the same frame and mechanism, and 
are frequently combined in one machine. The principal 
elements of such machines are—(l) the frame; (2) the 
pressure mechanism; (3) the clutches ; (4) the driving 

mechanism ; (5) the punches and dies. 

146. The Frame. 

The open-side or G frame is in general use, since it allows 
a greater range of work to be handled, and at the same time 
can be made rigid enough to stand the stresses which come 
upon it. Fig. 11G illustrates clearly the forms adopted by 
one firm of manufacturers, and shows the gradual increase in 
strength of back as the depth of throat becomes greater. 

The double machines consist of two single machines placed 

280 














PUNCHING AND SHEARING MACHINERY 281 


back to back, and driven by one train of gears so as to 
economise space. In such cases one of the machines is usually 
for punching, and the other for shearing. For very wide 
work, two of this kind of frames can be placed side by side, 
and some distance apart, like the housings of a planer. The 
shear blades extend from one frame to the other, and the 
work is fed between, making what is called a gate shear. 
Fig. 117 shows a large single machine of the open-side type. 
This shear has a depth of 60 inches from centre of cut to 
back of throat, and is capable of punching a 2^-inch hole in 



Fig. 116, 


The. Long and Allstatter CoHamilton, Ohio. 


l^-inch iron, or shearing a bar of flat iron 1^x8 inches. 
The general design and appearance of this machine are 
admirable. 

The closed or H frame is little used for the jobbing or 
general class of machine, on account of its limited range, but 
for special machinery, such as that employed for embossing 
and pressing sheet-metal forms, it is stronger and less clumsy 
than the open frame. 

Frames may also be classified as horizontal, vertical or 
inclined, the position of the frame being governed by the 
shape of the work to be done. The horizontal type as shown 






















































































































































































































































































































































LONC»*LLST»m» 



Sb’Lliid. tJNIHDNilcL HDNI 09 



























283 


PUNCHING AND SHEARING MACHINERY 

in Fig. 118 is well adapted for punching holes in flanges, 
while the body of the plate or bar is kept horizontal. In 
proportions and arrangement of driving machinery this form 
does not differ materially from the vertical ones just noticed. 
The inclined frame is generally made adjustable, so that it 
may be used either in a vertical or an inclined position. 









Fig. 118, 

HORIZONTAL 10-INCH PUNCH. 


The Cleveland Punch and Shear Works, Cleveland, Ohio. 

These machines are employed for special rather than for 
general work. 

O 


147. Pressure Mechanism. 

The pressure necessary to force the punch or die through 
the metal is obtained by the use of the eccentric, crank, cam, 
lever or toggle, as the case may be. Nearly all the machines 
illustrated and described in this chapter employ the crank 
and pitman form of motion, as it is simple and has the necessary 
increase of pressure at the end of the stroke. The lever machine 
such as shown in Fig. 119 is more common in iron and steel 
works than in the machine shop, and is obviously not adapted 
to punching. The toggle and cam motions are more often seen 
in presses for drawing sheet metal than in the shear or punch. 























284 MODERN AMERICAN MACHINE TOOLS 

The adjustment of the punch or upper die is effected in 
most machines by a screw thread and nut. Fig. 120 shows 
the head of a press with crank and pitman connection, and a 
right and left thread with turn buckle. 

Fig. 121 illustrates several of the methods of adjustment 
in common use. A shows plain right and left nuts with 
collar at centre for turning the screw, and U-shaped packing 
pieces between collar and nuts, making practically a solid 



Fig, 119. 

LEVER SHEAR—MOTOR DRIVEN—SHOWING KNIVES 
FOR CUTTING ROUNDS. 

The United Engineering and Foundry Co., Pittsburg, Pa. 


connection. B shows the introduction of a wedge for finer 
adjustment, while C represents right and left nuts with 
check nuts instead of packing pieces. Fig. 122 shows, on 
the other hand, the Stiles eccentric adjustment. As may be 
seen from the cut, the crank-pin bushing is eccentric, and by 
means of a gear and pinion can be revolved in its seat so as 
to change the length of the pitman. This arrangement 
makes a stiff connection without any screw threads. The 
lower end of the pitman in crank and eccentric connections 
usually bottoms directly in the plunger casting. 

On all machines which are to be used for shearing it is 
important to have the plunger slides large and some dis¬ 
tance apart, to resist the bending action due to the offset of 




































286 MODERN AMERICAN MACHINE TOOLS 

the shear blades. One disadvantage of the lever shear is 
the fact that the pivot is not well situated to resist the side a 



Fig. 122. 

PUNCH WITH STAYED GAP. 

E. W. Bliss and Co., Brooklyn, N.Y. 


thrust of the blades. Fig. 119 shows double housings at the 
joint, and the lathe re-enforced by a double yoke. When 
a machine is used for punching or for die work it becomes 






















PUNCHING AND SHEARING MACHINERY 287 


necessary to fit the slides carefully and provide means of 
adjustment for centring the dies. 


148. The Disengaging Clutches. 

Perhaps more ingenuity has been displayed in devising 
suitable arrangements for starting and stopping the motion 



Fig. 123. 

NO. 3 VERTICAL SHEAR, BELT DRIVEN. 

The United Engineering and Foundry Co., Pittsburg, Pa. 

of the plunger than in any other detail of power presses. 
The action of the shear or punch being so intermittent, and 










288 MODERN AMERICAN MACHINE TOOLS 

the variation of energy exerted being so great, it is necessary 
to have a fly-wheel and to keep it running at speed. In | 
practically all machines the fly-wheel runs loose at full speed L 
when the machine is not cutting, and is engaged or dis-1 
engaged by means of some form of clutch. In Fig. 123 a L 
simple jaw clutch is used, engaging with the main driving | 

gear. The machines 
made by E. W. Bliss i 
and Co. have the 
rolling-pin friction 
clutch, engaging the 
whole length of hub 
close to the shaft. 
The advantage of 
the friction clutch 
is the almost instan¬ 
taneous engagement 
of the wheel or gear 
when the lever is 
pressed. 

Fig. 124 shows a 
pin clutch of another 
type with the wheel 
removed. When 
the pin is in the 
position shown, the 
wheel runs loose on 
hub of collar. A 
partial rotation of pin causes it to engage with one of several 
recesses provided in hub of wheel. The starting lever is shown 
in the cut. All clutches on this class of machinery are arranged 
to be partially automatic. That is, after being engaged by a 
pressure on the treadle, they release automatically when the 
pressure is removed and leave the plunger at the highest 
point. If the pressure on the treadle is not removed the 
machine continues to act. Some machines have an adjust- 



Fig, 124. 

Perkins Automatic Clutch. 

The Perkins Machine Co., Boston, Mass. 




PUNCHING AND SHEARING MACHINERY 289 


able release cam or wiper, which can be so set as to disengage 
at any point in the revolution. On other machines a hand 
lever is used, by which the operator may stop the machine 
at any point in tne stroke. A brake which is thrown on 
by the stopping mechanism is also an important adjunct of 
machines which run at a high speed. A continuous friction 
on one end of the crank shaft sometimes serves a similar 
purpose. 

The punch illustrated in Fig. 125 has no clutch, and the 
shaft runs continuously, a ‘gag’ being used to start the 
motion of the plunger. This is pushed into position by 
the operator, and pulled back by a spring. 


149. The Driving Mechanism. 

The nature and the extent of the machinery for driving 
1 a power press depends upon the size and character of the 
machine. The smaller sizes have the fly-wheel on the crank 
shaft, and are driven directly by a belt or motor. The 
arrangement which is most common, and which is illustrated 
in nearly all the machines shown, is that of a countershaft, 
running at a comparatively high speed and carrying a fly¬ 
wheel, geared at a ratio of perhaps 6 or 8 to 1 with the 
1 crank shaft. In such cases the clutch usually engages with 
the larger gear on the crank shaft, although in some instances 
the clutch is on the countershaft. The service is so severe 
that unusual pains must be taken with the gear and pinion. 
k The pinion should have the teeth shrouded at the ends, and 
a large pitch must be used. Some makers half shroud the 
teeth on both gear and pinion. Forged-steel crank shafts 
are quite generally employed, and the type of the frame 
used in vertical machines is favourable to long bearings. 
In presses and shears for heavy work double gearing is 
often resorted to, especially with motor drives, as in 
Fig. 119. Electrical driving is frequently used to advan¬ 
tage on these machines, particularly on those of large capacity. 







MOTOR-DRIVEN LEVER PUNCH. 








PUNCHING AND SHEADING MACHINERY 291 


Nearly all American manufacturers are now prepared to adapt 
their machines to the motor drive when asked, and the 
adaptation presents no particular difficulty. 

150. The Tools. 

The plungers of most machines are adapted to receive 
either punches and dies or shear blades, as the work may 
require. The punches and dies used are of a standard 
pattern, the punch being of the flat-end form with a centre 
point, and the die flat but slightly convex on top. Punches 
having a spiral cutting edge are manufactured for the trade, 
but, so far as is known, comparatively few are in use. 
Experiments made by the writer several years ago demon¬ 
strated the fact that spiral punches developed considerably 
less resistance in going through the metal and injured the 
plate less than the flat form. 

The resistance offered to the spiral punch averaged more 
than 20 per cent, less than that of the flat form, and the loss 
of strength of the metal by punching averaged only 3 per cent, 
as against 7'5 per cent, for the ordinary punch. The penny- 
whistle form of punch also makes a shearing cut, and penetrates 
with less effort than the ordinary form. Users of punching 
machinery, who wish to do work beyond the ordinary capacity 
of the machine, can easily solve the problem in this way. 

The vertical adjustment of the punch is effected by chang- 
iug the length of pitman in the manner already described, 
while the two horizontal adjustments are made in the holders. 
The stripper should be made adjustable for different con¬ 
ditions. The shear blades can be set parallel to the frame of 
the machine for cutting, as shown in Fig. 123, or at right 
angles for splitting plates. 

151. The Lever Shear. 

This chapter would be incomplete without further refer¬ 
ence to that useful and powerful tool, the alligator or lever 








292 MODERN AMERICAN MACHINE TOOLS 


shear. The plain level- machine adapted for cutting only h 
illustrated in Fig. 119, which shows a large machine of thu 
class with a motor drive. As may be readily seen from th( 
illustration, this machine is operated by a cam on the mail 
shaft, while the lever is steadied by rigid guides. A steej 
plate takes the thrust and sliding off the cam. These 
machines are also arranged to be driven by a crank on the 
main shaft and a short pitman taking a knuckle bearing on 
the tail of the lever. The main pin is fast in the lever and 
oscillates in the housings on either side. 

The particular machine shown in the figure weighs, com¬ 
plete with 50 horse-power electric motor, 57,000 lbs., and 
is capable of cutting 4 x 4-inch or 5-inch round soft steel. 

Fig. 125 shows a punching and shearing machine with 
the G type of frame, but driven by a lever and cam 
instead of the usual crank and pitman. The starting and 
stopping of the plunger is effected by a gag which is 
operated by a hand lever. The machine is double-geared, 
permitting the use of a relatively high-speed motor. The 
machine illustrated in the figure is capable of punching a 
lj-inch hole in a 1-inch plate, of shearing 1-inch plate, or of 
cutting 2-inch rounds. 










Ji 

tbi 

tin 

niii 

tee 

ies{ 

tk 

: oi 
mt 


CHAPTER XI 

SCREW-CUTTING MACHINERY 


152. In General. 


k Various methods of cutting threads, either external or 
internal, have already been noticed. The use of the engine 
tl lathe for this purpose is not as common a practice as formerly 
1 on account of the slow and expensive nature of the process. 
Small machine screws and bolts are largely the product 


of the turret lathe or automatic screw machine, while longer 
id screws, such as those for machine feeds, are often made by 
kf the milling thread cutter described in Chapter VIII. 

After these are all accounted for, there still remain the 
0 larger and longer varieties of bolts used for fastenings, too 
big for the screw machine and not requiring the accurate 
but expensive finish given by the lathe or the thread milling 
machine. 

Such are usually threaded with chasing dies in the bolt 
cutter. Machines for cutting threads on pipe such as is used 
for gas, steam, or water, hardly come into the category of 
nachine shop appliances, since this work must usually be 
lone by the steam fitter. We cannot well avoid the con¬ 
sideration of them, however, as they resemble the bolt-cutting 
machines so closely, the same machine being sometimes 
adapted to both operations. 

They usually differ in the motions of the die and work, 
he bolt-cutting machine having a revolving die and station- 
ry holder, while in pipe cutting the work itself is usually 
revolved. 


293 







294 MODERN AMERICAN MACHINE TOOLS 


153. The Die Head. 

By far the most important element in the bolt cutter, and 
the one on which most care and thought have been bestowed 
by the designer, is the head for holding and adjusting the 
chasing dies. Figs. I 26a and 126b illustrate a type of die 
head which has been in long and successful use. The barrel 
or body of the head is of cast iron, but has hardened steel 



strips set lengthwise of its outer surface to take the wear of 
the die ring. 

The dies, four in number, slide radially in slots in a 
face plate which is fastened to the front end of the barrel 
by screws. The outer ends of the dies are guided by die 
caps, and these latter have sloping tops which fit correspond¬ 
ing grooves in the die ring. 

As the die ring slides forward or back on the barrel these 
sloping grooves move the dies in or out in a manner which 
may be readily understood from the figures. 




















































SCREW-CUTTING MACHINERY 


295 


The wearing surfaces are faced with hardened steel to 
reduce the wear to a minimum. 

The die ring is moved by a rocking lever and link not 
shown in the cuts, and controlled by the movement of the 



< 


Fig. 1*266. 

THE ACME DIE HEAD, SHOWING HARDENING STEEL STRIPS 

IN BARREL AND DIE RING. 


clutch ring on the barrel. An adjusting screw at the con¬ 
nection between the die ring and the link makes it possible 
to so set the combination as to give the exact size of cut 

desired. 

A bronze ring fitting the groove in the clutch ling is con¬ 
nected with an automatic opening and closing device operated 





























































296 MODERN AMERICAN MACHINE TOOLS 


by the machine itself. On the later machines of this make a 
separate adjusting screw renders it possible to open or close 
the dies for a roughing cut without disturbing the adjustment 
for a finishing cut. 

In this machine the dies are radial, the cutting edge being 
slightly ahead of the centre, as seen in Fig. 126. The dies 
are reamed in position and cut by a master tap, which is 
slightly smaller than the bolt to be cut. 

When the die is adjusted to size, the fact that the cutting 
edge is ahead of the centre will ensure the necessary clearance. 



Fig. 127. 

DETAIL OF THE STANDARD MORGAN DIE-HEAD. 


The dies are then reamed with a taper reamer giving a 
throat at the entrance, and the heels of the dies are filed 
back to the centre line. Fig. 127 shows a die head of some¬ 
what similar construction, there being the radial dies, the 
die caps, and die ring, as in the one just described. 

The locking of the dies in the closed position is effected 
by the taper plunger K fitting in the adjustable bar B. The 
clutch-ring O lifts this plunger by means of the lever M 
during the back-lash interval, and then pulls back the die 
ring itself, opening the dies. The opening and closing can be 
performed automatically or by hand. 

Fig. 128 illustrates an entirely different type of die and 
head. The teeth on the die, instead of being tapped or 











































































SCREW-GUTTING MACHINERY 


297 



bobbed in the usual way, are milled on the flat side, and the 
dies are set at such an angle in the head as to present the 
correct cutting edge. 

They are set almost at a tangent to the circumference of 
the bolt, and are also inclined to the plane of rotation to 
correspond with 
the obliquity of 
the thread. 

In other words, 
they correspond 
to the threading 
tool used in a 
lathe, and can be 
ground on the 
end indefinitely 
without changing 
the shape of the 
cutting edge. 

The dies are 
hardened and tem¬ 
pered the whole 
length, so that 
they can be used 
until too short for ~ - 

further grinding. Fig. 12 s. 

The grinding pro¬ 
cess is simpler 
than in the dies 


PATENT BOLT CUTTER. 

The Landis Machine Co., Waynesboro’, Pa. 


before described, and does not require as much expert skill. 
At the same time, the introduction of the straight in place 
of the curved clearance would not seem to be so favourable 

to endurance and to smooth cutting. 

This is a question which can only be settled by experience. 
The blocks which hold the dies oscillate on spindles for 
opening and closing the cutting edges, and the spindles in turn 
are operated by the usual clutch ring with automatic release. 




2-INCH SINGLE BOLT CUTTER. 

The Acme Machinery Co., Cleveland, Ohio. 


This arrangement assures a long and rigid bearing for the 
spindle, and removes the belt from danger of being spattered 
with oil. Four changes of speed is the usual number. 

Fig. 130 represents a pipe-cutting machine, where the 
speed changes are effected by gearing. 

As in this machine the work revolves instead of the dies, 
the spindle carries a gripping chuck at the front and a 
centring chuck at the rear end. 


298 MODERN AMERICAN MACHINE TOOLS 

154. The Driving Mechanism. 

The nature and arrangement of the driving mechanism 
naturally depends upon the size of the work to be done. 
Practically all machines, however, are geared, the spindle 
which carries the die head having a gear at the rear end, as 
in Fig. 129, engaging with a pinion on the cone pulley shaft. 


Fig. 129. 


SCREW-CUTTING MACHINERY 


299 


The belt runs always on one pulley and never needs to 
be bandied, the six speeds of the spindle being obtained by 
manipulating the levers in front of the headstock. The 
spindle is driven by a large gear on the front clmck. 



Fig. 130. 

4-INCH PIPE THREADING AND CUTTING MACHINE. 

The Standard Engineering Co., Ellwood City, Pa. 


Small Machines are usually so arranged that they can be 
driven either by power or by hand. 

Machines similar to that shown in Fig. 129 are sometimes 
made with two or three beads on one frame. 

155. Carriage and Feed Mechanism. 

The carriage of a bolt cutter usually consists of a simple vice, 
manipulated by screw and pilot wheel, for gripping the work. 

Tb e vice is attached to a plain slide operated by a rack 







300 MODERN AMERICAN MACHINE TOOLS 


and pinion. These features are shown in Fig. 129. In the 
pipe-cutting machine (Eig. 130) the die head is carried in 
a somewhat similar manner upon a sliding carriage, and also 
has a transverse adjustment. Behind the die head is a 
tool post carrying a cutting-off tool. When this is in use, 
or when work is to be removed, the dies can be slid aside 
out of the way. 

In ordinary bolt cutting the thread of the bolt itself may 
be depended upon to move the carriage during the operation 
of cutting. 

When the thread has been cut to a sufficient distance the 
carriage automatically opens the dies and then closes and 
locks them again after the reverse. 

When coarse threads are to be cut, or when special 
accuracy is desired, a lead screw attachment can be had with 
such machines as that shown in Fig. 129. It is of course 
necessary to provide a separate lead screw and nut for each 
pitch, but they are so constructed as to he readily changed. 
When a machine is confined to one class of work few changes 
would be necessary. 

Screws can be cut in this way which are nearly as accurate 
as those made in an engine lathe, while the time of cutting 
will be about one-tenth as long. 

156. General Design. 

The single cabinet with overhanging frame is the most 
common type, as may be seen by reference to Figs. 129 and 
130. The cabinet is provided with a broad base, and is 
usually one casting with the bed or ways. 

The headstock may be bolted on, as shown in Fig. 129, 
or the whole frame of the machine may be one massive 
casting, as in Fig. 130. The overhang of the slides is 
balanced by a corresponding overhang of the headstock, or 
by the driving pulley and gears, as in Fig. 129. Special 
attention is given to this type of frame because the author 


SCREW-CUTTING MACHINERY 


301 


regards it as a particularly good design for machines having 
short beds. The conventional or lathe type of frame is 
sometimes used. 


157, Feeds and Speeds. 

The following table is published by the Acme Machinery 
Company of Cleveland, Ohio, and represents American practice 
in the matter of speeds, corresponding to a surface or linear 
speed of from 10 to 20 feet per minute. The same table can 
be applied to nut tapping. 

Table of Speeds for Cutting Bolts and Tapping Nuts. 


Diameter. 

10 Lineal 
Feet per 
Minute. 
Revolutions. 

15 Lineal 
Feet per 
Minute. 
Revolutions. 

20 Lineal 
Feet per 
Minute. 
Revolutions. | 

1 

g 


460 

612 

1 

4 


230 

306 

5 

1 6 ' 


188 

244 

3 

8 

... 

153 

204 

7 

1 6 


131 

176 

1 

2 


115 

153 

9 

1 6 


102 

136 

5 

Q 


93 

122 

3 

X 


75 

102 

7 

S 

• • • 

65 

88 

1 

38 

55 

76 

n 

34 

50 


u 

30 

45 

• • • 

if 

28 

40 


ij 

25 

38 


G 

23 

35 


if 

22 

32 


u 

20 

30 


9 

19 

28 


2-1 

4 

17 

25 


2i 
^ 2 

15 

22 


93 

14 

20 

... 

3 

12 

18 


‘U 

9 4 

11 

... 

... 

3J 

10 



Q3 

9 



4 

8 




































302 MODERN AMERICAN MACHINE TOOLS 

158. Nut-Tapping Machinery. 

As has been already noticed, most boring and drilling 
machines can be easily adapted for tapping by using proper 
chucks for the taps. This type of machine is, however, better 
adapted for tapping holes in castings or forgings which have 
been drilled in the same machine. For the simpler operation 
of nut tapping a multiple spindle machine somewhat similar 
to the multiple drill is efficient and economical. Such a 
machine is made by the Acme Company. 

The spindles can be run at the same or different speeds, 
and are so driven by clutches that any one spindle may be 
stopped when necessary. 

The spindles are counterbalanced and have spring sockets, 
so that the taps may be removed and replaced when the 
machine is running. 

Four speeds are provided, and the machine is adapted 
to nuts from |--inch to 1|- inches. 

All bolt-cutting and nut-tapping machines should be pro¬ 
vided with oil pumps, and for this class of work only pure 
lard oil or a mixture of lard oil and soda water is suitable. 

159. Thread-Rolling Machines. 

For producing screw threads on rough wire or forged 
blanks the rolling process has been used with success. The 
blank is rolled between two dies having grooves of the right 
pitch and inclination, and the thread is raised by displace¬ 
ment of the metal, so that the finished screw is larger in 
diameter than the blank. One die is usually stationary, 
and the other is reciprocated by a crank and pitman. 

An automatic feed is attached when large quantities of 
screws of the same size are to be threaded. Machines are 
made of various sizes for threading wire from ^-inch up to 
1 inch in diameter. 

Cold rolling a thread in this way on soft steel would tend 
to raise the elastic limit and the ultimate tensile strength of 
the metal. 


CHAPTER XII 


TENDENCIES IN MODERN MACHINE DESIGN 

160. General Remarks. 

A study of the machine tools which have been put upon 
the market in this country during the past year or two Avill 
reveal some marked characteristics which may perhaps show 
something of the immediate future of machine design. The 
most of these have been noticed in previous chapters, as 
evidenced in particular classes of machines, in lathes or 
planers or milling machines. 

A somewhat broader view of the machinery field will 
show that these characteristics are more or less common to 
all classes of machine tools, and that they point to certain 
definite tendencies in design which must be understood if 
the future is to be read aright. 

The most noticeable tendency is uncpiestionably that 
towards the more general use of the electric motor, either 
directly or indirectly. 

The majority of the larger machines illustrated in this 
book are adapted for electric transmission, and some are 
especially designed for connection with motors. The use of 
variable or constant speed motors, of countershafts or direct 
drives, will be discussed later. It is enough now to notice 
that electric driving is an established fact, and that machines 
in future must be so designed as to accommodate the motor 
and the controllers. 

Another noticeable tendency, and one which is more or 

303 




304 MODERN AMERICAN MACHINE TOOLS 


less a corollary to the one just mentioned, points to the 
gradual abandonment of belts on machine tools and the 
substitution of gears and silent chains. Compactness and 
unity of design call for a motor bolted to the frame of the 
machine, a location which usually makes the line of centres 
too short for the successful application of belts. 

The evil of the short belt and the inconvenience of the 
speed cone have led to the substitution of gear boxes in feed 
mechanism on all classes of machines. There seems to be no 
good reason why a similar change may not benefit the driving 
mechanism. The amount of gearing necessary for speed 
changes is again dependent on the type of motor used, and 
this subject is reserved for later discussion. 

The great increase in power and capacity for work which 
is so marked a characteristic of modern machinery is more 
or less involved with the tendencies already noticed. As 
a result of keen competition among those who use such 
machinery there is a continual striving for increase of output. 
Every additional piece that a given machine will finish in a 
given time, represents not only a saving of interest on its 
cost but a saving in labour and in every item of shop 
expense. 

The use of wider and faster belts, of heavier gears and 
spindles, and of more massive frames, means more power 
and more work per machine. Reference is not here made 
to the increase in size of machines which is also noticeable, 
but rather to the concentration of metal and of power in 
medium-sized machines. 

The 16-inch lathe of ten years ago consumed but one 
horse-power, and that only when crowded to the capacity 
of its narrow, sluggish belt. The modern lathe of the same 
swing will consume double the amount of power, and, if 
specially fitted for the use of high-speed steels, may use 10 
or 12 horse-power. 

The increasing use of high-speed steels is another factor 
which must be reckoned with by designers of machinery in 


TENDENCIES IN MODERN MACHINE DESIGN 305 

the future. Its use is not confined to lathes and planer tools, 
but is extending to twist drills and milling cutters. 

Finally, machine tools are being made more automatic in 
character, and both the number of cutting tools and the 
number of simultaneous or consecutive operations are being 
largely increased. The various developments just mentioned 
will be considered somewhat in detail in this chapter, and 
some further data and illustrations given. 

161. Electric Driving. 

It is not necessary at the present time to argue in favour 
of electric transmission. The superior economy of this kind 
of driving, the clear head room afforded for crane service, the 
greater cleanliness and light due to the absence of overhead 
belting and shafting, and the flexibility as regards changes 
and extensions, are all familiar reasons for its general adop¬ 
tion. 

The recent improvements in speed control furnish another 
potent argument for the use of the new motive power. The 
question to-day is not so much whether to use electricity, 
but how to use it to the best advantage. The manufacturer 
must first decide whether he will use individual motors on 
each machine, or whether it will pay better to group his 
machinery and use short line shafts driven by motors. In 
general it may be said that large machines, consuming more 
than one or two horse-power and run at widely varying 
speeds and loads, should be equipped with independent 
motors. 

Smaller machines which are more or less alike, and which 
are run continuously on uniform work, can be economically 
grouped together in bunches of from six to ten and driven 
by a shaft either overhead or underneath, the shaft being 
connected to the motor by belt, chain, or gears. If the shaft 
runs at a moderate speed, the connection with the motor may 
be such as to permit of the use of a relatively small high- 

u 


306 MODERN AMERICAN MACHINE TOOLS 


speed motor, at a considerable saving in first cost. If the 
machines have an intermittent, jerky motion, like planers, 
shapers, or presses, the shaft had better run at a compara¬ 
tively high speed and be equipped with one or more fly¬ 
wheels to equalise the load on the motor and permit of the 
use of a smaller unit. 

The next important question to be decided is that of the 
type of motor to be selected, whether direct or alternating 
current, constant or variable speed, and if variable speed, 
how the motors are to be regulated. 

If the group system of transmission is to be employed, 
the alternating current with induction motors offers the best 
solution on account of the simplicity and durability of this 
type of motor. It has no rubbing contacts, and requires no 
more care than an ordinary countershaft. 

In such case, all speed changes and all stopping and 
starting must be effected mechanically between the line shaft 
and the machine, or in the latter, since the induction motor 
must at all times run in phase with its generator. The 
motors can be stopped or started from the engine-room the 
same as shafting, and of course any motor can be disconnected 
by means of a switch. The direct-current exciter can be 
made large enough to supply current for power if desired. 

If variable-speed motors are to be used, either wholly or 
in part, the direct current will usually be the more economical 
and convenient, since it can be used equally well for constant 
or variable speed machines. A direct current may be 
obtained from the alternating system by a motor generator, 
but this is a rather expensive method. 

On large machines with individual motors it is well to 
have electric speed control, and this may be effected in 
several ways. 

1. By introducing resistance into the armature circuit. 

2. By introducing resistance into the shunt Held circuit. 

3. By a multiple voltage system of wiring. 

4. By a combination of two of the above. 







TENDENCIES IN MODERN MACHINE DESIGN 307 

The objection to No. 1 is the waste of energy in the 
rheostat, and the variations of speed with change of load. 

No. 2 can only be used for increasing the speed above 
the normal, and that only to about 30 per cent, on account 
of sparking at the commutator. 

No. 3 is the method which is received with most favour 
at present, either alone or in combination as in No. 4. 

The three-wire system with two voltages, as introduced 
by the Westinghouse Company, is probably the best known 
of the multiple voltage arrangements. By means of a 
specially constructed generator a difference of potential of, 
we will say, 250 volts is maintained between the two outside 
wires, while the middle wire differs from either of the others 
by 125 volts. 

A 250-volt shunt motor being connected to the outside 
wires, runs at normal speed, but when connected to one of 
the 125-volt circuits, runs at half speed. Speeds intermediate 
between half speed and the normal, or speeds above the 
normal, can be obtained by method 2. 

The four-wire system as installed by the Allis-Chalmers- 
Bullock Company, furnishes six independent voltages of 60, 
80, 100, 140, 190, and 250 volts, by the various combinations 
possible, and thus gives a much greater range of speeds 
than the three-wire, and with finer gradations. It is entirely 
possible to obtain the intermediate speeds with shunt field 
resistance, since the intervals correspond to about 30 or 35 
per cent. 

In order to obtain these different voltages it is necessary 
to use, in addition to a 110-volt generator, a motor generator 
of special design, and this in addition to the cost of wiring 
makes the system rather too expensive for ordinary shops. 
A three-wire system similar to the above differs from the 
Westinghouse, inasmuch as it has three voltages instead of 
two. 

Summing up the various systems outlined, it may be said 
that it is possible with some loss of efficiency to obtain a 









308 MODERN AMERICAN MACHINE TOOLS 

speed variation of 2 to 1 or 100 per cent, by a two-wire 
system using methods 1 and 2. 1 bat with a three-wire 

system a speed variation of 2 to 1 can be secured economi¬ 
cally, and 3 or 4 to 1 by the use of shunt resistance. That 
the four-wire system gives a range of 4 to 1 directly, and 
by the introduction of resistance a possible variation of i 
7 or 8 to 1. 

In any of these systems the motor will need to be larger 
than if working always at the maximum speed. With the 
rheostat control this increase will be as the square of the 
speed variation, while with the multiple voltage the size will 
increase in the same ratio as the speed variation. This is a 
strong argument in favour of the latter method of regulation. 

The next problem that confronts the owner of machine 
tools is that of mechanical versus electrical speed control. To 
a certain extent this is dependent on the electric system 
used. If constant-speed motors and the group system are 
selected, it naturally follows that the speed must be regulated 
entirely by mechanical means. 

When independent motors are used on each machine, 
electric speed control may be adopted to whatever extent 
seems desirable. Most of the electrically driven machines 
which have been illustrated in previous chapters are equipped 
with constant-speed motors and change gears. This method 
permits of the use of relatively small high-speed motors, but 
does away with the advantages secured by electric control. 
The objection to step cones is the coarse scale of speed 
gradations and the time consumed in shifting the belt. 
Nests of gears are more convenient and will be more used, 
but even these do not afford the fine gradations which can 
be obtained by the use of the electric controller. 

For machines of small or medium size the combination of 
the constant-speed motor and the change gears is satisfactory, 
but larger and more expensive machines should have a more 
complete scale of speeds, and the speed control should be so 
convenient that it may be used at all times and the machine 

















TENDENCIES IN MODERN MACHINE DESIGN 309 


always run at the exact speed which will give the maximum 
output. 

These results are best attained by the combination of a 
variable-speed motor with mechanical devices, in such a way 
that the coarser gradations are obtained by the gearing, and 
the intermediate shading is done with the controller. For 
large machines a three-wire system, combined with rheostat 
control and giving a total speed variation of 4 to 1, will 
usually answer all requirements. At the beginning of any 
particular operation the mechanical control can be adjusted 
so that the normal speed of the motor will give the average 
speed desired. 

If the electric controller is properly located for the con¬ 
venience of the operator, he may then, without leaving the 
work, shade the speed up or down as the character of the 
operation may require. Planing, shaping, and slotting 
machines will need only the electric control, as this will 
give the necessary range of speeds. Variable-speed counter¬ 
shafts have been used to some extent in place of the electric 
controller, but it is safe to say that, up to the date of this 
writing, no entirely satisfactory device of this character has 
been put upon the market. 

With tools of medium size, a 2 to 1 electric variation, 
combined with change gears, gives a satisfactory solution. 
The best means of connection between motor and machine 
is still an unsettled problem. 

The various methods still employed have already been 
illustrated in former chapters—belting, gearing, and chain 
drives. It is probable that the use of the belt on machine 
tools will be very limited in the future. 

To furnish the power necessary to drive the modern 
machine a belt needs to have either excessive width or 
excessive speed, and is certain to be displaced ultimately by 
the silent chain, as the latter is stronger, more compact, and 
more positive in its action. 

Under some circumstances steel and raw-hide gearing is 




rirf 

Jo. 

o 


o 


o 

o. 




K 


28-INCH PONI) NEW MODEL ENGINE LATHE. 



























TENDENCIES IN MODERN MACHINE DESIGN 311 

preferable to either of the above, making possible a more 
compact and self-contained machine. 

One feature of electrical control that deserves special 
notice is the possibility of locating the controller near the 
hand of the operator, so that, without moving from his 
position or taking his eyes from the work, he may instantly 
change to the desired speed. 

I his means that he will be much more apt to use the best 
speed than if he has to travel the length or the width of a big 
machine and shift a belt or change a gear. 

o o 

One thing more needs to be done, and that is to build 
machine tools with special reference to the electric drive. 

Too many of the modern machines show by their appear¬ 
ance a clumsy adaptation to electric motive power, rather than 

a convenient and harmonious design. 

© 

This is due to the fact that it has heretofore been neces¬ 
sary to consider both mechanical and electrical means of 
driving in the same machine at some sacrifice for either. 

Electrical transmission has now reached a point in its 
development where it justifies the building of machines 
intended for electric driving exclusively. Some of our 
machine tool manufacturers recognise this, and are now 
advertising such machines. 

The new model 28-inch lathe shown in Fig. 131 is a 
good example of a machine built for the motor and a motor 
built for the machine. A variable-speed motor is used 

having a range of 2 to 1. The controller is at the right 

of the carriage, and by its means fifteen speeds can be 

secured. By means of another crank on the apron four 

changes of gearing are made possible, making in all sixty 
different speeds which can be controlled by the operator 
without leaving the work. 

Another tendency, already hinted at in what precedes, 
is evinced by the increasing demand for stronger and heavier 
machines. 

The 18-inch lathe of a decade ago weighed perhaps 



6-INCH FORMING LATHE. 














TENDENCIES IN MODERN MACHINE DESIGN 313 


2000 lbs., was capable of taking only a light chip at the 
full swing, and consumed a maximum of perhaps 2 horse¬ 
power under the most favourable conditions. A modern 
lathe of the same nominal capacity weighs, we will say, 
3000 lbs., and if designed for use with high-speed steels, 
will consume from 5 to 15 horse-power. So many examples 
have been given in previous chapters that it is not necessary 
to do more than allude to this development here. 

The remarkable growth in the use of turret lathes and 
forming machines for reducing metal is but another step in 
the same direction. Some of the records made by machines 
of this class in removing large quantities of metal and in 
finishing large numbers of parts in a limited time have already 
been noticed in Chapter IV. 

One of the largest turret lathes yet made is illustrated 
in Fig. 132. 

This machine is adapted to the use of high-speed steel 
tools, and is capable of handling bar stock 6 inches in diameter. 

The spindle is driven by a 7-inch belt, and twelve speeds 
can be obtained without stopping the machine. As an 
example of the capacity of this lathe, it may be said that a 
locomotive wrist pin 4^ inches in diameter and 10^ inches 
long over all has been finished from 4^-inch steel bar stock in 
eighteen minutes. 

Fig. 133 illustrates the latest development of the flat 
turret’ lathe electrically driven (see Fig. 49). 

The use of the high-speed or air-hardening steel is natur¬ 
ally one of the principal factors in the increase of output. 
Although this class of steel was first invented and applied 
by Americans, it must be admitted that up to the present 
time our British cousins have made more use of the inven¬ 
tion than we have ourselves, and they know more of its 
possibilities. 

American manufacturers are now waking up to the import¬ 
ance of the new discovery, and machines are on the market 
which are specially adapted for its use. 









TENDENCIES IN MODERN MACHINE DESIGN 315 


One of these has already been illustrated as in Fig. 37, 
and another is shown in Fig*. 134. 

A 30-inch rapid-reduction lathe exhibited at the St. Louis 
Exposition was equipped with a 25-horse-power motor, a fact 
which speaks plainly as to what is expected in the way of 
removing metal. 

Mention has been made in Chapter VII. of the results 
obtained in high-speed milling. 

Experiments recently made by the Cincinnati Milling 
Machine Company, and reported in the American Machinist , 
throw some light on the endurance of high-speed steel when 
used in milling cutters. 

An ordinary spiral mill of Novo steel, running at a surface 
speed of 82 feet per minute and with a feed of 27 inches per 
minute, has cut 6800 inches of grey cast iron without sharpen¬ 
ing, or more than live times what an ordinary carbon steel 
cutter could do at about half the feed. 

Other tests with cutters of various shapes gave similar 
results. 

There is no doubt as to the fact that machine tools are 
becoming more elaborate and complicated. 

While this in itself is a disadvantage, it may be justified 
by a greater capacity and a larger output. Every machine 
must be judged by the ratio of earning power to interest on 
the investment, and if a certain tool costs more than its neigh¬ 
bour, it must do better work or more work to pay for the 
difference. 

It is but fair to the new tools to say that the added 
complication has come about from the attempt to solve the 
problem of speed and feed control satisfactorily. It is not 
enough to provide the proper gearing for speed and feed 
changes, but it must be so arranged that the changes can be 
made by the operator without too much trouble. 

The endeavour to bring the reversing gear and the driving 
speed control to the apron of the engine lathe has been 
responsible for much of the increased mechanism which is so 




Fig. 134. 

30-INCH PATENT HEAD LATHE. 





























































TENDENCIES IN MODERN MACHINE DESIGN 317 

evident, and similar statements may be made in regard to 
other machines. 

Specialisation is the order of the day, and to a certain 
extent the turret lathe and the milling machine are bound to 
displace the engine lathe and planing machine. As has been 
already noticed in other chapters, a multiplicity of tools and 
of cutting edges, which enables a machine to perform a 
number of operations simultaneously or consecutively, is the 
characteristic of special machines. The remarkable records of 
work done by such machines are due to this characteristic, 
and are only made possible when large numbers of similar 
pieces are to be finished. 

For the ordinary work of the machine shop and for 
operations on single pieces our old friends the engine lathe, 
the planer, the drill press, and the boring mill will always be 
needed. They will be more powerful, more convenient, and 
more automatic in action, but they will continue to be the 
mainstays of every shop doing miscellaneous work. In all 
metal-cutting machinery, the general tendency is and will be 
to increase the amount of work done by the machine and to 
reduce to its lowest terms the human labour required. 


INDEX 


Bolt-cutting Machine, 293. 
Boring Mills, 126. 

Boring head, 148. 

Capacity and weight, 150. 
Cross-rail, 133. 

Cylinder, 155. 

Driving mechanism, 139. 
Electric transmission, 139. 
Feed mechanism, 149. 
Frame, 146. 

Housings, 133. 

Housings, double, 128. 
Housings, movable, 144. 
Horizontal, 144. 

Large, 153. 

Miscellaneous, 159. 

Movable housings, 144. 
Power and capacity, 141. 
Single-post, 127. 

Sliding head, 150. 
Stationary head, 146. 

Table, 129, 149. 

Tilting table, 155. 

Tool heads, 135. 

Vertical, 126. 

Cutting Speeds— 

Bolt machines, 301. 

Drill presses, 183, 196. 
Lathes, 83. 

Milling machines, 216, 315. 
Planers, 24. 

Design, General, 303. 
Drilling Machinery— 

Arm, radial, 175. 

Base, 172. 

Column, 160, 172. 

Driving mechanism, 178. 

318 


Drilling Machinery— continued. 
Feed mechanism, 168, 182. 
Gearing, 182. 

Head and spindle, 164. 
High-speed, 196. 
Miscellaneous, 188. 

Multiple drill, 188. 

Power and capacity, 186, 194. 
Radials, 171. 

Radial arm, 175. 

Speeds and feeds, 183. 
Spindles, 164. 

Tables, 185. 

Tool head, 178. 

Upright, 160. 

Electric Drives— 

Boring mills, 139. 

Lathes, 92. 

Planers, 27. 

Systems, various, 306, 309. 

Feed Control— 

Boring mills, 149. 

Drill presses, 168, 182. 

Lathes, 73. 

Milling machines, 207. 

Planers, 18. 

Shapers, 42. 

Gear-cutting Machines, 229. 
Automatic, 230. 

Planing, 242. 

Shaping, 237. 

Grinding machines, 249. 
Classification, 249. 

Cutter and reamer, 273. 
Cylindrical, 257. 

Cylindrical wheels, 255. 




INDEX 


319 


Grinding Machines— continued. 
Disc wheels, 252. 

Drill grinding, 269. 

Emery wheels, 278. 

Ring wheels, 253. 

Surface grinding, 250. 

Tool grinding, 265. 

Universal, 262. 

Key-seating Machines, 49. 

Lathes, 58. 

Apron, 80. 

Automatic, 114. 

Automatic screw, 120. 
Automatic chucking, 121. 
Bed, 58. 

Bolt, 102. 

Carriage, 78. 

Chucking, 114, 121. 

Cutting speeds, 83. 

Electric drives, 92. 

Extension, 97. 

Facing, 102. 

Feed control, 73. 

Flat turret, 112. 

Forming, 118. 

Gap, 97. 

Headstock, 62. 

Hexagon turret, 110. 

Horse power, 87. 
Miscellaneous, 104. 

Power and capacity, 124. 
Railroad, 103. 

Reduction or roughing, 99. 
Speeds, 83. 

Speed gearing, 68. 

Spindles, 64. 

Spindle, double, 99. 
Tailstock, 81. 

Tool-maker’s, 102. 

Turret, 107. 

Turret tool post, 115. 

Vertical turret, 123. 

Milling Machines— 
Advantages, 198. 
Attachments, 211, 215. 


Milling Machines— continued. 
Classification, 198. 

Chucks, 213. 

Columns, 199. 

Driving mechanism, 206. 

Feed mechanism, 207. 

Heads, 203, 212. 

Heavy, 52. 

Highspeed, 216. 

Lincoln, 217. 

Manufacturing, 218. 

Power and capacity, 226. 

Profiling, 221. 

Spindle, 203. 

Table, 201. 

Thread, 245. 

Vertical, 223. 

Vices, 213. 

Nut-tapping Machines, 302. 

Planing Machines, 2. 

Bed, 2. 

Combination, 22. 

Crank, 32. 

Cross-rail, 10. 

Cutting speeds, 24. 

Electric drives, 27. 

Feed mechanism, 18. 

Gearing of table, 14. 

Horse power, 25. 

Housings, 6. 

Open-side, 20. 

Reversing gear, 17. 

Rotary, 50. 

Table, 5. 

Tool head, 13. 

Widened, 19. 

Power and Capacity— 

Boring mills, 141. 

Drill presses, 186, 194. 

Lathes, 87, 304, 313. 

Milling machines, 226. 

Planers, 25. 

Turret machines, 124. 

Punching and Shearing Machinery, 
280. 

Clutches, 287. 





320 MODERN AMERICAN MACHINE TOOLS 


Punching and Shearing Machinery— 
continued. 

Driving mechanism, 289. 

Frame, 280. 

Lever Shear, 291. 

Pressure mechanism, 283. 

Tools, 291. 

Screw-cutting Machinery, 293. 

Die heads, 294. 

Driving mechanism, 298. 

Feed mechanism, 299. 

General design, 300. 

Nut tapping, 302. 

Speeds, 301. 

Thread rolling, 302. 

Screw Machines, automatic, 120. 

Screw Threads— 

Cutting, 293. 

Milling, 245. 

Rolling, 302. 

Shaping Machines, 33. 

Column, 34. 


Shaping Machines— continued. 
Cross-rail, 38. 

Countershaft, 43. 

Draw-cut, 45. 

Driving gear, 40. 

Electric driving, 43. 

Feed mechanism, 42. 

Miscellaneous, 56. 

Open-side, 45. 

Ram, 35. 

Table, 38. 

Tool head, 36. 

Traverse, 44. 

Vertical, 47. 

Shearing Machinery : see Punchin 
Machinery. 

Slotting Machines, 47. 

Vertical Machines— 

Boring mill, 126. 

Milling machines, 223. 

Shaping machines, 47. 

Turret machines, 123. 


Printed by T. and A. Constable, Printers to His Majesty 
at the Edinburgh University Press 


















1 V' A‘> ’ 

: 


n <>* ' 

C c5» 


\ 


3 % \K - v , 


Kt% 
> </> 


~%f> A 
</> ,< V 


. v ** 


SB?/ ^ % \WM: *?% : .1 


<f> 

<?*» 




. 0 *' t » N S "V' ** s \*>\*' 1 * * ^o/" ' ./c 0 s c */%, ' °* 

L> 0 Csfs- /• 'P ,|T0 A *SKL- 1 O C » ^ 



A "TV >■ 

„ \ V V -<. of- 

o,r <^r t ' 

\V ^ ^ fl i A ° A 

' * ' *", > " . 0 ^ s 

«? <S| * , \"o ^ 

j&;V e * 

. A ^ *.^SR 

> ^ ^ *,w; a 

A < 3 l y „ _ , * 



'*0 0* 


, 


°-;, » .-> n o ’ 0 ^ 



* O 




<s . 

:*w 

^ ® A 

V \> (#> 

tc ^ - ' Or' 

\v < * 0 ^ » » . ' * s 

V * > Sy V s 

'■ -Vi l* isfiA) ^ •>£* <A ^ 

A* A' rv ,•'- / 7 e ^ <o 

a- <\V ® ^Ssww/yl 7 ^ 

vr ; 




"54, 

< J 


A ☆ 


X 


0 O 


,0- 



o 5 ^ 






* <* 


/- 


A 

,V « v 1 8 * «&> 

A * ■* ^ 

*P, A * 

vO o * 

\ A ✓> 

TV*"/^ ’"' / s'v;■->%>*» v ^\s.< 

* 9 ® ^ ^ aV * 

- A> c 

\/ T r?’ * * ’V •>* u> 

r-- Jo ’^ /.» c . < < ."‘ •*'' 'a x ..u/i"' 1 -'* A' 0 n c 

°o A* * ls0Z>L\ °° o°- ^ 

' ^ r - en N 







A o.v ' 3 '-?' “ 



•>V V 

o o x 


o5 ^ 









* o o' 

%> 7 Ts>>° 4 .., e ^'* B TT’*V’ 

^ " 0 ^ > s 0 ^ » c* v N ^ * 0 /- > o> 



* . V* ^ 

V .v ^ 

y 0 « >- ■* a0 <* 

' 0° ^ 
C V" 

o 5 ^ ^ ^ 



, ,^ v V = ^ 

*ys$&* - ^ oV 

J * * s ^ a\ w \ I 0 k ' ° * K * •& . 0 N c - '< 5 ^ ' a 

^ .V ^ v 9-> 0 0 k ^ . X 



V ^ -* 

<» 1 * 

% % * 

' > ' 0 V S SV * '* %> K> 

* <* £>«** ^ <&' 'tt. - x 

° ^ c,^ -' - "A* A^' ■* 

\WW///£ 7 V 7 _ V \V 

' ' *'\\}Mt : .<r '*■ * 


•>^ V o it. 

oo' « % 




74 - 


\ 


0 


\ pyj 
| "V * <0 

C S 



O if , n ^ O.V - C> i 

s o « > V o N 0 V V ^ * 1 * ♦4’ 

s '// c> \» N a v * 0 „ > 4 cy^ s 

^•xf Tiv VY< / Ol y V 


t> <r 


^ ;7' '” 

^ V*' ; 


s A 

a\ . * v 1 * M *t 


C. y^V 

,v > ^ 


’^7- y 0 * X 



0 V < A 

r c° N ">p ^ ** A x .a 


\ 


0 o 
























■>* V 

o „ 


^ % 

•e- ^ - 

® V 

Z \ Z «£, 

O <V ^ <r> o If, \>c< \ \V 

* -V j “t t >^0> * V 

v 1^ 4 'f ^ O.V s 

'**'VV ,, « V 0>< >° cO-,V 

• v S ^/Y}^-, 1 '-^ G * -r-Ws. <*■ “P 

•" "s c^' -; A \W. ^ 

^ ^ o /s^^lk* - 
>- 


<j5 x* 

> A * 

0 * «$• r >r ^ p-'J 

0 V », n * 

aV v 
</X <* 

tS 


-V 


~_J* * "oo^ 

X0 o * 

0 O ^ ^ CL' rl* l» ' N O j. 

c-G ^oso 0 ■v a , a * <0‘ ~o ^ 

v S * « / j S u \V V ft n -‘"V. tf 1 ' Ni <, 9 S , *t* 

V </ O ** O v s r /, C‘ 

* *fj T* (<2 S* * . ^ .^•/'’^W •* -<i 

<?G *\> ^ jA'v<-'A, r ->G <A * -.. <?* V 

- ,^ V 'V « w ss u, 

4* . ** V * ftt 

'V^Vc"-, 

. *4 p \J I> - ~ 

x> <4 

= z ',/- V' " _, •>*_ ^ 

<1 ... ,, „ __ . , 

ft- 


2 § % - 

•a/ <P » 

ft ^ e- -i oV > v . 

^ x ' ,v ^. y j. \ •£• 

^ - 
^ n 

* x 0 o. 

«, X 4^ y> 


V 

o o x 


^ WINVV' > \ 

c ‘ * o ‘ 

", v _»’ ^“ 4 . 

r> 


v, ’ ft? 

“tP. ,\V ^ fCvN 

v 5 ^> 


•GG <i 
<s V 


p O 
O 

< v) 

A* ,r> 

>* r ^ ^ ^ ^ , V* 

‘y 3 N0 ' v<" ‘°g^ ' 8111 / 3 r 

^ ^ n&-'^ °. % $' * 

A v ^ o 

fc ^ ^ "ft 1 '^ 

s> a x v .« %* ■ / °* ^ 

aX ^ &((l///X-> + , < 

v : i- °b ^ 



1; c><^ - 

•%■ y V 5 *>tf, o i/w 
i ^\‘ - x 

^ * S s \' X 

% -Mr- /*4 * ^\ oVlfi* r 



t * 0 f 


r>. 

L ~ " ■- 


^7 » « 

<i 

. A 

r* 

o o 


A 

c? 


. y a\ _., . . 

s'* y : v • ”° 0 ' * 

\V 

vn y J, CG- 

^ * 0 K 0 ° 4^ r -G> 

G> \ > ^ ^ * 0 z > 

> V* ^ 



\ 00 *. 







































































































